Are you a casual gamer, who happens to like pain? Have you struggled, but managed to finish and get all of Spelunky 2's achievements within a reasonable time range, but still couldn't finish Cosmic Ocean? Not even get close to finish it? I know. It's evil, dark. and it really crushes the "just above average" players, like myself.
If you don't relate, congratulations! You're either really skilled or wise enough to know that you don't want to suffer. Still, I hope you enjoy this guide :steamhappy:
However, if that's literally you, I may have some tips that can turn that 7-5 death into a 7-70 death, or maybe the special ending!

The final goal of this guide is to complete Cosmic Ocean, but there are other objectives that can, and most probably will, increase your rate of success. Those are:

• Get to Cosmic Ocean before 40 minutes (ideally around 25 minutes).
  
• Get well equipped to Cosmic Ocean.
  
• Have at least one ace in the hole.
  
• Have great knowledge of each area of the game: Their layouts and their dangers.

Without any delay, here's the main recipe for this guide:

1. Get through 1-1 as fast as possible.
   
2. Rob the first shopkeeper, but don't kill him.
   
3. Avoid the angry shopkeeper(s) or die trying.
   
4. Killback (kill Quillback).
   
5. Prefer Volcana, but you should go Jungle once in a while.
   
6. Van Horsing is very important for Temple route. Ooba's sisters are complicated.
   
7. If you have the resources, DO THE OLMEC SKIP and get the Ankh.
   
8. Prefer going Temple of Anubis over Tide Pool.
   
9. Try to skip Qilin if you feel confident enough to fail, die, and get back to where you died.
   
10. Get comfortable and keep your cool while sailing through the Cosmic Ocean.

But first, I must tell you...

Dying is probably one of the first words that comes to mind when you think about Spelunky in general, though it comes right after suffering.
You can learn with every bad thing that happens in this game, so don't let stress get in the way of that. Try to analyze what happened and how you could've avoided those bad scenarios.
I know the ideal mindset and playstyle isn't the same for everybody, but I heavily advocate for the fun way. Have a laugh at absurd deaths, record clips of unexpected stuff, and celebrate improvements. Take your time, and be confident to take as many steps forward as possible.
Cosmic Ocean needs CHILL. Best case scenario, you'll be there for 94 levels where anything can lead to the abrupt end of your journey. The OST of this area begs you to stay calm and relaxed, in order to focus on everything you've learned so far. If you wish to listen to it while reading this guide, I think that would be an awesome idea. https://www.youtube.com/watch?v=YcnS_ow2yvI

Starting with Dwelling, this area will cover the first four main steps of this guide. They are:

Level 1-1 has no udjat eye, no foreground shop, no Kali altar... nothing really worth that isn't also present in other levels. If you spot a wooden crate, you should always get them if you can (even if you have to use a bomb or a rope to reach them). Save the pet only if it's in the way to the exit, or if you're with 2 HP or less. Save a rope, by the way!

The first shopkeeper should spawn in 1-2, and he can sell some really good items, including the jetpack and bomb boxes. You should definitely rob him if that's the case, and there's a really straightforward, skill-independent way to do it: Stand right where he stands, throw a rope, grab his shotgun, and then you simply walk away from his store, getting all his items without a care in the world. Shopkeepers were heavily nerfed from Spelunky HD, where they would jump around everywhere at incredible high speed. In Spelunky 2, you can somewhat avoid him if he's unarmed. It's pretty rare to die to this shopkeeper, since he'll probably be unarmed, alone, and stunned for a little while when you're pillaging his store.
If you get his key instead of his shotgun (in case he has a locked background room), it's fine. The shopkeeper will be way more deadly now that he's holding his shotgun, but as long as you keep your distance, it should be fine. Also, this key can be used in Volcana 2-1 in order to free Van Horsing from his cell, so you won't need to look for the key in there.

If you robbed the shopkeeper, he'll be angry at you in the next level. Which means that shopkeepers will try to shoot you on sight in their shops or by the exit door. Try to not touch any shopkeeper and not get shot, and you will be forgiven in the next level.
PS: In some levels, it's extremely difficult to avoid his shots or even himself, so you can and most probably will die in some cases. But it's fine, you will probably only lose a couple of minutes from the run, worst case scenario.
PS: You can kill him at 1-3 if he seems to be hard to avoid. It's pretty easy to juke him at 1-4.

That's right, you should kill Quillback every single time. It's pretty easy, and he gives you a bomb bag and a turkey in return. Here's every item that will absolutely wreck him:

• Paste: Throw a bomb at him, he explodes and dies.
  
• Shotgun: Shoot him 2/3 times, he dies. Be careful not to shoot his dropped bomb bag!
  
• Spike boots: Do quick jumps about three times on his head. Dead.
  
• Ice gun: Freeze him, then whip. RIP.

Even if you don't own any of the items above, you can just throw a bomb when he's finishing digging a tunnel, and he might die. Not guaranteed, though, but it's pretty reliable.

With the second area of the game, we advance two more steps into our objectives.


Volcana:


Jungle:


Vlad's cape alone justifies my preference for Volcana, and even if you found a Jetpack in Dwellings, making it way more dangerous, I still think it's worth going Volcana for Van Horsing. Jungle hasn't much other than regular items, a chance to get a Jetpack, and Paste if you find a giant spider. But its difficulty makes it worth to go through it all. Cosmic Ocean most certainly will have at least a Jungle level, and if you're not used to it, you will most probably fall prey to plague doctors and maneater plants.


Van Horsing leads to Alien Compass in Temple 4-1, which is a wonderful item to have in Cosmic Ocean, while the three sisters reward is a bomb box, which is good, but they also get angry if you attempt to do the Olmec skip. That means that not only they have a subpar reward in comparison to Van Horsing's, they will also hinder the best time save of the run.

Now we reach Olmec, Spelunky HD's first final boss. This leads to a boss battle with 3 stages, which ends with getting the Ankh. Normally, this battle lasts for at least 2 minutes, and is accompanied with some dangers.
For a long while, I beat Olmec the way god Derek intended. Though, after I noticed for how long usually it goes, and that I can die with the explosion of the UFOs in the last stage, I decided to see if it was feasible to skip this part with the Ankh. Maybe it would make a difference, right?
...

I can't express how great it is to be able to skip this fight. Here's a small cheat sheet of the resources you will need:

• Have at least 5 bombs (2 for waddler, 3 for the skip).
  
• Have at least 1 rope IF you have Pitcher's mitt.

Worst case scenario, you will find no bombs in stores or anywhere. Though, if you spent a maximum of 2 bombs to kill Quillback, you should have at least 5 bombs with you, and considering there's always a route to the end of the level that requires 0 bombs and 0 ropes, there's a very high chance you will have the resources to skip Olmec and get the Ankh.

The following YouTube videos will cover every skip.

No paste and no mitt: https://www.youtube.com/watch?v=ME5x82s24-8
Paste: https://www.youtube.com/watch?v=dw269S-RNNo
Mitt: https://www.youtube.com/watch?v=hX0N6LJJgtw

PS: It's also possible to not use a rope if you have the Pitcher's mitt. However, it's far more difficult. You can try this if you want, but I don't recommend it: https://www.youtube.com/watch?v=Dt1s-avz5WY

After Olmec, we are presented with two options:

• Tide Pool: A sea themed level with spiked corals, a samurai crab guy, a big fish, and momma Tusk.
  
• Temple of Anubis: A better representation of hell than Dante's Inferno.

With that said, hear me out...

I believe Temple of Anubis is a way better option than Tide Pool, and I was able to progress way further into the Cosmic Ocean once I started to choose Temple. Let's compare both like we compared Volcana to Jungle.

Tide Pool:


Temple of Anubis:


PS: Duat can be skipped if the player has found a Jetpack previously, since it can be used to skip Qilin. Skipping Duat saves the Ankh.

Even though, through Tide Pool, you can make it to Cosmic Ocean with 99 bombs, 99 ropes, Vlad's cape, Kapala, Ankh, and get +8 HP within Madame Tusk's Palace, I don't think that's as good as Temple of Anubis' Alien Compass, Elixir, and Jetpack.


Alien Compass is probably the best tool you can wish for to reach 7-99 for the first time. Knowing the location of Cosmic Ocean's exit doors at all times is an absolute game changer: You can track your pathing without worrying about forgetting of the location of the exit; you can plan your way relative to the position of the exit; you can predict from where the celestial jelly will come from...
(How to get it: Find Van Horsing in a background room of Temple of Anubis 4-1)

Clone Gun, on the other hand, can be used to clone the player bag in the Sun Challenge containing 24 bombs and 24 ropes 3 times, and achieve at least a total of 96 bombs and ropes. Having 99 bombs and ropes is extremely useful for Cosmic Ocean, but it's just so much work (Helping Hand needs to carry the clone gun from 4-2 to 5-1, and Sun Challenge might not spawn in 7-1), for such an unnecessary extra that it really pales in comparison to the much simpler and effective Alien Compass.
(How to get it: Complete Tide Pool's Star Challenge in 4-2)


Starting with the Ankh, it's needless to say it's a contender for the best item in the game. It allows the player to survive death once, unconditionally. It has basically no flaws, other than it forces you to go Tide Pool and do the Ankh skip in 4-3 in order to fully benefit from it.
(How to get it: Reach the background layer of Olmec's lair, 3-1)

The Elixir, however, is an item you get from completing the Star Challenge in 4-2, just like the Clone Gun. It protects you once from getting cursed or poisoned and doubles all healing while active. This means that, with the Kapala, you will earn two hearts anytime you fill it, and you will earn 16 hearts by sacrificing a pet to Kali. Even though this won't save you from getting crushed, eaten, exploded, and won't save you from spikes, corals, and lava, it will basically means a second chance against curse, from witch doctors and cat mummies, and will prevent poison once, which are very common and very unpredictable run enders.
(How to get it: Complete Temple of Anubis' Star Challenge in 4-2)


Jetpack is, easily, Spelunky HD's best item. In Spelunky 2, however, people are way more scared of it, as it only takes a fire damage for it to explode, deal a lot of damage to the player, and send them flying. If the player survives all that, they will be left without a back item, which is really really bad. Though, without this huge flaw, it retains all great characteristics from its predecessor in HD.
(How to get it: Defeat Anubis II in Duat, Temple of Anubis 4-4)

Vlad's cape doesn't offer the mobility of the Jetpack, but it doesn't have any other downside. It allows the player to double jump and glide at will, and it will never catch fire and explode. It's a safer option that may seem like an absolute winner in comparison to the Jetpack, but it's a little bit more complicated than that.
(How to get it: Defeat Vlad in Vlad's Castle, Volcana 2-2 ~ 2-4)

With the Jetpack, Volcana and Neo Babylon will become drastically deadlier, but it will make Temple of Anubis way easier to navigate, including dodging crush traps and cat mummies. Other than that, Dwelling, Jungle, Tide Pool, Temple of Anubis, and Sunken City won't offer any dangers to the Jetpack, offering the player the best mobility without any downsides.

With Vlad's cape, Volcana and Neo Babylon will be way safer, but Temple of Anubis will be way harder to navigate through. Any other area will be worse in comparison to the Jetpack, but Vlad's cape's double jump and glide will still offer great mobility.

In short, both are very good. Jetpack is a high risk/high reward, and its nemesis are Neo Babylon and Volcana. Vlad's cape is a safer option with a great reward, and its nemesis are Temple of Anubis and Jungle.


Alien Compass is way better than Clone Gun, Elixir is a little bit worse than Ankh, and Jetpack is a little bit better than Vlad's cape. Besides, training Temple for the Cosmic Ocean is a huge, huge extra. Tide Pool in CO is a breath of fresh air.

Go Temple of Anubis.

These last levels, 6-1 to 7-4, have little to no interesting stuff, and you should be well equipped to get through them without much issues.

The most interesting topic is the Qilin skip, that can be performed two ways.

The easiest way is with a Jetpack and a few ropes. You can see more of it here: https://www.youtube.com/watch?v=GKQpyVeGf6o
The other one, way harder, is with Vlad's cape and climbing gloves. I tried it some times, failed it all: https://www.youtube.com/watch?v=XfqzTiMvkZE
PS: You don't need to do this skip if you've been doing Qilin's quest so far. Just get Qilin instead :)

For the sun challenge, I usually go to the top left or top right corner and spam whip, and it almost always works. However, this video might show the most consistent way to do it: https://www.youtube.com/watch?v=wmF0U4yHY5k
Hundun is pretty easy, just throw some bombs at one head, then do quick, successive hops on top of the last one. That is, if you got the spiked shoes (guaranteed to get, just defeat Yeti Queen with a bomb or with a mine, in 5-1).
There are some other ways to do it, but they also involve some level of danger and skill, so in this case it's probably better to "waste" some bombs.

If you did everything right, you should get to Cosmic Ocean with your game looking like this:

• Run time of 25 to 40 minutes;
  
• At least 30 bombs and 30 ropes;
  
• Alien Compass + Jetpack;
  
• Elixir is your ace in the hole.

It does seem worse in comparison to Tide Pool's alternative route (that guarantees an Ankh), but as it was shown, those three items as better options than Tide Pool's, even without the Ankh. But one very important aspect of these runs is that you're choosing the hardest area over the easiest one, and this choice will absolutely help you improve in Cosmic Ocean for whichever route you take in the future.

With that, all the four objectives of the intro are complete, and Cosmic Ocean would soon be conquered, bit by bit. As stated in the beginning, try not to stress too much about failing, because there's not enough resources to guarantee you won't. Ever. Your best shot is to improve, and to never forget to have fun.
If you've been to CO before, you might know the drill: Destroy three orbs, avoid the celestial jelly awakened from the orbs, head towards the exit and don't die to anything else. And then repeat it for 94 levels! Also, don't take too long, or another celestial jelly will appear after three minutes in a level.
Now, this part is up to the player to decide how to tackle these problems, but here's my strategy:

1. Smack the first orbs you see, and always keep track of the number of orbs.
   
2. Start looking for orbs away from the exit, then get closer to it.
   
3. By the last orb, find a clear path towards the exit.
   
4. Know that it's a bad idea to fight every single enemy. Some are so deep in the level they won't pose a threat unless you disturb them.
   
5. Be patient with the jelly. It won't touch you if it's circling you, giving you a lot of time to plan your next moves.
   
6. Two jellies can technically become one if you make them circle you.

Now, for each area...
You should clear dart traps at the left and right edges of the level. Also, clear dart traps near the exit beforehand. Clear any dart trap, that is. Be careful with hedgehogs.
In Minecraft, they tell you to never dig straight down. In Volcana, never go straight up. There can be a Spikeball just above, or an Imp that will drop a magma pot on your head. Go from top to bottom, you'll thank me.
Clear enemies from the top of the level. I had two runs end because I fell to the top of the level and it had a lot of enemies there. Also, always get the boomerang.
Be happy. Don't mess with any enemies other than the zombies and you should be good.
Speed is your enemy here. Plan your every move, and start with the edges of the level, circling towards the center. Be damn afraid of cat mummies, but get rid of them if you can. You can also expect a big crush trap to spawn just above the entrance, so be ready to make a move.
Expect unseen explosions in the first seconds of this level. Find a cover, then start exploring when you feel it's safe. Probably the second easiest kind of level.
Keep your senses sharp. UFOs can collide with energy balls and go flying towards you. Also, pray no UFO will hit a lava container. Be extra careful.
Other than poison darts and regenerating blocks, this level poses little to no danger. Same as dwellings, clear all dart traps, especially those at the left and right edges of the level and near the exit.
This concludes this guide, and I really wish to give a nice perspective for those who are looking for one. I recently finished Cosmic Ocean for the first time with about 280 hours of playtime. You should be able to make it with way less than that.
I made a YouTube video of some funny moments of my most recent runs. You can see it here:

I will also try to record some stuff to exemplify the topics and I will update this guide if I do so. Until then, I hope this was enough :D