This will be a small walkthrough on how to get through the different parts of the game, all the way up to the ending. I will be giving small tips on each mission.
This guide will only focus on progression and not on grinding/making money/secrets.
Please note that my native language is not English so there might be a few spelling mistakes or general errors around. I apologize for any of those.
Anyway, Enjoy!.

Game begins with a lot of nostalgia. Play as either Ryan or Alex and get all the way to the top to defeat...Simon?

Defeat Ivan.
Go inside the gym and defeat everyone to fight Otis. He is only vulnerable to special attacks. (RB if you are using a controller)

On the first floor there's a vending machine, punch it to get drinks to heal.


Go to the next floor, defeat everyone and fight Tex. He is only vulnerable to weapon damage. Time to go up to the final floor.
The classroom is open, you can go in to talk to Cyndi. You can also save your game here.

Once you exit the classroom defeat everyone to fight the twins Andy and Randy.
Use the elevator, fight Simon and... Congrats! you just finished the tutorial.

After selecting your character, you will appear at R.C.H.S.
You have 5 minutes to get to your classroom. You can explore around the school or head straight to your classroom. Which is exactly one floor above your current one. It's the one everyone is heading in.

After a few scenes you will be attacked by Abobo and several Policemen. You can fight or run the choice is yours but the experience is always helpful.


Get out of the classroom and start heading down the school, all the way to the lobby. Your character will talk about a vent making noise, hit it, proceed and you will end in the sewers.

In the future, if you are being chased by the police, you can use trash containers or hideouts to stop them from chasing you.

Just keep moving and you will eventually pop out at Alex and Ryan's car shop (And Roxy). Follow the story and head outside with them.
You will have to clear each screen of enemies in order to proceed. Keep following Alex and Ryan as you proceed right and you will find Purple Bee.

Defeat Purple Bee (not that difficult) and Alex and Ryan will join you. Head back to the car shop to continue.

It is recommended you buy some moves at the dojo (where you fought Purple Bee) and get some money/levels before you continue with the story. You can check the guides about grinding money for more info.

After you feel confident you grinded enough, head to the arcade, which is one screen left from the dojo where you fought Purple Bee.
In here, you can defeat all the nerds to trigger a boss fight. Defeat the nerd and continue forward.

You can pick him up and throw him away from the robot to make the fight easier.


You can now take the subway or keep moving right through the minigolf place. Since we just defeated the Nerd boss we are going to continue through the minigolf field.
From here onwards keep heading right on every screen you find. You will bump into a few shops and a house with a pug graffiti, which is a hideout.


Keep moving right and you will eventually end up in a factory with a lot of luchador enemies. You have to defeat all of them on each screen of the factory which includes: the entrance, the first level inside the factory, the second level inside the factory and the back of the factory.
Once you defeat all the luchadors, Pink Bee will appear at the back of the factory, he is not that difficult but has more health than Purple Bee.


After defeating him, do as Alex and Ryan said, head West, you will go through a small shopping district with a new dojo with new moves.


Keep heading west, you will arrive at a gym with a subway station. Take the subway, exit and you will appear one screen right from the car repair shop.
Head inside thecar repair shop to trigger the next event.

Listen to what Roxy says, save if needed and continue towards River City Bridge.
To get there, you must head left from the repair shop.
Once you arrive you will find a very suspicious fence at the left side, you can climb it in order to access a secret area.


In this area, defeat every single enemy and after you are done, head slightly to the left side near the water to make Rocko spawn


He will escape from where you came from. You are supposed to chase after him and punch him once to make him speak. He runs all the way to the repair shop. If you aren't able to catch him, you can go back to the secret place behind River City Bridge, defeat everyone again, and he will spawn again.
After you get him, head to the repair shop again.
Once done, start heading left again until you reach Grotto Street. There you will find Chan Wuk Park, head inside, go up and to the left and you will find the entrance to the sewers.


Defeat all enemies here (Warlocks can get annoying so have patience) and Tex will spawn.
You have to chase him through the sewers. This part can get pretty difficult so have a lot of patience, grind for agility food if needed and keep trying until you get him. If he gets too far ahead from you, you can head back to the sewers entrance to fight all the warlocks and make him spawn again.


Occasionally, Tex will fall into the water as soon as you start chasing him inside the sewers. The only way to fix this is to head back and make him spawn again. If you give him a slight head start it is more rare for him to fall into the water.

After punching him, listen to what he says and head back to the car shop. You will be told to go the roof of R.C.H.S. at night.
To get to the school, just take the same path you took to get to Chan Wuk Park but instead of heading inside the park, keep heading left. You will eventually arrive at the school gates.

You have to wait until night time (indicated by a black and cyan clock at the top right) in order to make Ivan spawn at the roof. You can waste time inside the school grinding or unlocking the 2 secret characters, Rudy (school gym) and Mike (school cafeteria)

Head to the roof, defeat everyone here and Ivan will spawn.


You will have to chase him too. It is difficult to get him since he runs super fast, just be patient. If he gets to the school gates he will escape and you will have to head back to the roof to make him spawn again (which again can only be done at night)

After you punch him he will tell you that Otis was around the school.
Wait until it's daylight, head to the school gates and then go left, into the school's football field.

Defeat everyone at the football field to make Otis spawn (can only be done during the day)
He will fight you. If you stay close to him you can dodge most of his attacks.


After defeating him he will tell you that there is a fan of Slick around the school's basement

Head to the school lobby, then downstairs to arrive at the basement.
In here you will have to pick up the crowbar (location in picture) and then head to the door at the far right.


Inside this room you will have to hit the vent at the top right with your crowbar and then head inside
Sometimes you slide down instead of going inside the vent. Just stand close to the opening and it should still teleport you to the next screen.

Once inside, fight all the warlocks and then Ether. Once you defeat him, he will tell you to go to the old school.


To get to the old school, head to the car repair shop, then take the subway that's one screen to the right. Once you exit the subway you should be at the gym. Head left from the gym and you should be at the old R.C. high school.
Bring some food or healing items because the fighting can be pretty intense.


Once inside the school, clear every room/floor of enemies to proceed. You will also have to release all the tied up teachers.
Keep clearing each floor until you eventually reach the elevator. Head to the roof and ... Slick will be there!


Fight Slick, he can be pretty tough if he gets going.
Once you defeat him, congrats! You just...beat the game? Already? No, there's more...

So you defeated Slick...already?
If you saw the cutscene you know it's not over.
Head to the repair shop, you can take the subway back next to the gym.
Roxy will tell you they cleared the blockade at Chan Wuk Park, head there next.
Once you get to the park, head right and you will find a new path, take it and you will go through a forest.


Keep heading right through the forest. There's an intersection you can take, but Cindy's house is all the way to the right. Keep heading right until you get to the city.

You will find a screen in the forest called *Crossed Streams Forest - Ancient Tree *. If you defeat all the luchadores here you can fight both Purple bee and Pink bee together. Be careful in case you are low on health.

After you get to the city find the house that has the halloween decoration, head inside and hey! It's Cindy.


Talk with her and she will tell you that in order to stay, you will have to bring back milk. What? That easy? Lets go get the milk then.

In order to find the milk bottles, you have to head all the way back where you came from to Chan Wuk Park. Once you get to the park, head right and to the shopping district (the one with Mao's shop and Wanna' Sauna). There will be a small cutscene, defeat everyone and get yourself a bottle of milk from where the skater girl was standing (you can pick up a milk bottle with B on an xbox controller)


Now comes your most challenging mission yet... you have to bring back the bottle of milk, without getting hit once, all the way from the market to Cindy's house.
Not only will you be slowed down by the milk but you can't even fight back while carrying it.
There are many tips in order to clear this mission but the truth is...you have to be lucky and have a lot of patience.


You can watch that video to see some of the following tips in action.

• You can run the first 4 screens as long as you just keep moving. These include Waterfront Mall, Sticksville 2nd street, Grotto St. and Chan Wuk Park.
  
• Once you get to the first screen of the forest, zone in and out from Chan Wuk Park until you get no enemies spawn close to you. This will ensure you have enough time to safely put the milk down (by pressing B with the xbox controller) and fight all the enemies before picking it back.
  
• You can do that previous trick in every screen except Crossed Streams Falls, since there's no enemies there.
  
• If you are fighting every enemy, remember 2 more enemies will spawn after you clear the whole screen. Wait for those 2 to spawn and defeat them before moving onwards.
  
• If you clear all the enemies at Crossed Streams Forest - Ancient Tree, remember you will have to fight Pink and Purple bee, even if you defeated them before.
  You can skip this fight if you grab the milk and run while they are speaking
• Don't run in the forest, you might collide against a stone accidentally and drop the milk. As long as you killed all the enemies you can take it slow and easy (enemies will spawn again if you take too much time but it takes a while).
  
• When you get to Crossed Streams Falls, remember you can run and jump to get a better distance and height.
  
• Be careful where you leave the milk and never fight close to where it is.
  
• Be careful once you get to Cindy's house, as there's one more fight you have to do before you can go inside with the milk.
  
• Once you are heading inside Cindy's house with the milk, DON'T RUN, you might bump and lose all your progress and have to start the milk delivery again.

Once you get close to Cindy's house with the milk, get ready to fight the skater girls.


Once you defeat them and bring the milk in... you are done! enjoy the cutscene and the fruits of your effort. Breath deeply, get a snack and a drink and get ready for the next part.

Originally posted by Linux MrSchism:

Milk quest has been improved to allow a few hits on the bottle.

The milk bottle can now take about 3 hits making it easier to deliver.

After you are done with the milk delivery, remember to save! Please save!
Cindy will tell you about some weird helicopters and military men around town.
Head outside and scan around for helicopter shadows.
The shadow can spawn in any of these locations:

• Hazel Ave.
  
• Rollingwood - Suburbs.
  
• Rollingwood - Park.
  
• Rollingwood - Donwtown.
  
• McNamara Street.

Just keep moving back and forth from these locations to make the shadow spawn. Once you see it, chase it to the next screen. Wait a bit at the next screen and a soldier should drop down from a helicopter. Fight him and keep doing these back and forth until you have defeated 6 of them.



Once you have all 6 dog tags head inside the military base at Rollingwood - Downtown. It's the sign that says Bravo Fort and Keep out.
Once inside the base defeat all enemies and fight the soldier to get the hint about where to go next.


Head to McNamara street, to the club with the powergl... with the videogaming glove statue outside.
Once inside the club defeat all enemies and head to the stairs at the far right.
After a short elevator ride you will arrive at the roof. Defeat all enemies here again and Adam will spawn. Defeat him to get a hint on where to go next.



I recommend you head to Cindy's house to save and to do some intense shopping/grinding before heading out to your next location.

Once you feel confident enough in your strength. Head back once again to McNamara Street, the place with the club. If you head one screen right from there you will appear in Lil' Tokyo.
Once there, head left and then up, towards the market area.



Keep heading left from here until you arrive to a weird vertical screen called Merville - Cashill Street. From there head all the way up and to the right

There's a subway station here in case you want to go through that.


Keep heading right through the bikes and you will arrive at Merv Enterprises. Head towards the sign that says Parking.


Once you get to the Parkade, defeat every enemy here and get on the lift. You will start going up.
Keep punching and defeating enemies until you eventually get to the top. Your character will automatically get inside the building once you do.

Once you are inside the building you can head all the way right, avoiding fights, until you get to the Finances Dept.
From here onward, you will have to get at least 1 keycard to proceed. To get a keycard, you have to defeat all the enemies until one of them drops it. Note that you only need one, every enemy you kill after that will still keep dropping keycards but you don't need them.

You can hide behind the yellow cubicles or the columns to avoid the damage from the plane

You can also hug the far right wall in order to avoid all the damage from the plane and let your enemies take some fire.



You will have to defeat enemies and get keycards for 3 rooms, and in each one the airplane will be firing at you.

Once you get to the lobby you have to again get one more keycard and then you can finally proceed to Merv
(Note) I didn't need to use a keycard to get past the lobby, try it and see if it works for you

Talk with Merv and Chris will appear, if you don't remember Chris, she is the leader of The Flock, your gang, she is mentioned at the beginning of the game.
Keep watching the cutscene and you will eventually find yourself facing Wes.
Just be careful not to fall and you should be fine.


Keep watching the events and both Wes and Chris will join you!
Get ready as you are getting close to the end!

Okay so after you are done with Merv's building all the enemies look...weird? They also don't drop money and are a lot more difficult to fight. Note that the men in black characters do drop money, a lot of it actually, in case you want to grind a bit more. They also give a lot of experience.

To progress the story we are going to head back to Cindy's house. After the interesting cutscene, head back to car repair shop.


On the way there you will bump into a weird alien at River City Bridge, follow him and he will take you all the way to the school. Ignore that for now and head back to the repair shop.


Talk to Roxy, now head Chan Wuk Park, ignoring the alien guy.
Here you can fight a boss called ME. Be careful, he loves punching you when you fall to the ground.


Now head to the bridge again and chase the alien guy all the way to school again. If you can't make him spawn, get to river city bridge from the left side.
After chasing him to the school gates, defeat everyone here and ... Slick will appear!. As with most bosses, he is not that strong unless you let him get rolling. Defeat him and you should be able to get inside school.


Once inside the school, get to Hall - B, that's 2 screens up from the school's lobby.
In there defeat all the enemies around and Proto will appear! Defeat him.


After you defeat him, something will happen...

So that locker leads...to...River City Underground? Uh? Sounds familiar...
Anyway...
It's recommended that you get a lot of healing items and be pretty strong to finish this area.
Ride the elevator down and read the weird and interesting tooltips.
Once you get all the way down head right, jump over the trucks and go through the door on the right.


On the next screen, you will have to defeat all the men in black, be careful with the guns.
Head right once you defeat everyone and on the next screen just rush to the door that says 25-B, go inside.


On this screen you will have to defeat all the men in black while dodging electric lasers, don't worry, the laser doesn't hurt you but it does stun you.
After you clear that room, head right once again and you find Dr.D!


After his dialogue a lot of clones will start poping out. The idea is to defeat the machine and not the clones themselves. The machine can only be damaged when clones are out, so try not to defeat them and just endure their hits while you take it down.
You can attack the machine from the side to avoid getting hit by the electricity.


Go through the cloning machine (where the tubes with clones where coming out) and head downstairs, then all the way to the right, and upstairs again. Be careful not to get hit by the enemies while you are going upstairs.
On the next screen there's a small secret if you go all the way up (poor Abobos). Head all the way right but be careful not to fall. The treadmills can be tricky.
You will arrive at a playground like area, ignore it and keep going right.
In here defeat all enemies and after you do it... Dr.D will appear again! This time you will fight him. He can be pretty tough and can use an attack that will switch your controls, be careful.


After you defeat him...It's time to run! you will have 3 minutes, be careful and try to run back as carefully but quickly as possible.
Once you get to the Underground Base Vault... the true boss will appear!


To defeat him you can only hit him with high attacks. A good technique is to jump and kick/punch him, move to a side to avoid his counter and repeat. This will put him on a loop until he is defeated.
After you beat the boss, it's not over yet!
Run away before the whole place explodes. Be careful with the dudes in flames as they can easily stun lock you on the ground forever.


Watch the cutscenes at the end and...you did it! Congratulations! You finally completed the game.
Enjoy the credits!

I hope the guide was helpful to you. If you want me to add, change or remove anything from the guide leave a comment. I will try to do so as soon as possible. But be patient as it might take a while. Do the same if you find any spelling mistakes or syntax errors, I tried my best to read everything again but there might be a few mistakes still.
Hope all the info helps!