This is a guide that will hopefully be built by the community. This is also the first guide I've made, so any formatting suggestions are appreciated!

Freeride has a lot of secrets, and each one I've found so far have been so fun to find, but I want to find more and help y'all find them, too! If you have secrets you found, please put them in the comments and I will update the guide (and give you the credit). They will generally be displayed in order of appearance in the game.

Since this is a secrets guide, there will be spoilers. I will cover each secret with a spoiler tag, but leave the location unspoiled, so proceed with that in mind :)

Thank you to celestialandromeda, siff, The Bismarck, brrbrrbatappim, Vanton253, oz, Wavuvi, and T0talZero for you contributions and corrections. Without you, this guide wouldn't be nearly as complete or helpful. Thank you again!

Total secrets: 14
Currently found on this guide: 14/14

At the train platform:
When Lepida asks if you want to go on an adventure, say no or stay silent (...). She will wait for you to change your mind, and you can walk around. Straight up leave, either by going left or right on the road in front of the station. She will try to convince you to stay a couple times before you unlock this secret and the achievement "No".

On the train, in Kad/Dakuiri's car:
Kad is planning to trip you: but you can simply avoid him by walking on the seat close to the camera until you reach Lepida. You save him a beating, and you a fall! You also get the achievement "Dodge Kad's Trip".

In the engine room:
1. Before or after talking to Lepida (but without doing the tutorial), you can pull the lever, Kronk! This skips the tutorial on telekinesis, so make sure you know what you're doing (Or you just like doing things the hard way, I won't judge *P)! You'll also get the achievement "Skip the Tutorial".
2. If you stand still in the engine room for long enough (about 30 seconds), the fate train will neigh at you. You will also receive the achievement "Wait Like She Told You To"

Approaching the town (these first two were found by siff. Thank you!)
1. "Eavesdrop on Dennis and Lepida: I got this one by jumping off the top of the rainbow path into the fenced in water below, then running around back up to the top by the co-bini cat store. From there you can approach and listen to the conversation."
2. "Found their Apartment achievement can be found by locating the Brokenheart service door, near the beach, entering Kad and Dak's birth year (2192, found on the back of the red-cerulean badge dropped by Hephaestus: see Sewers section), then go into their private room." Their private room is located through the backstairs in the kitchen.
3. You can eavesdrop on Solo's confession to Kohno by accessing the backstairs of the arcade. To do this, make sure you haven't committed to any routes. Go to the ice cream storefront and enter the door to the right of it. You'll unlock the "Eavesdrop on Solo and Kohno" achievement.

Kad's Route:
(Thank you to siff and Wavuvi for finding this!)If you throw an object at the punching bag with full power in the arcade, you will unlock the achievement "-POW-".

Exploring the Sewer (find Pino):
1. When you find Pino inside the Sewer, go to the tunnel she's closer to. Keep going until you find her bow. When you pick it up, a huge slug demon with drop from the sky: simply pick them up. You've now met Googly! :D You'll also get the achievement "Ouuuuah~". Also also, did you know you can put Googly in your pocket, along with other slug demons?
2. After finding the bow, follow Pino, and she'll lead you to the underground slums. Alternatively, you can just go right (opposite of Pino) when you find her in the Sewer. You'll get the achievement "Found the Sewer Town".
3. Fight and defeat Hephaestus. You'll get the achievement "Speared the Boar", and then leave to unlock the secret.

Wandering above the arcade:
This secret was found by siff :) "The achievement "Oh no Ribbert" Can be found by wandering around in the tunnels ABOVE the arcade {this can be found via the Inner Rotunda route. See 'Secrets with multiple ways to achieve' section for how to get to the Rotunda.}. Ribbert falls into the seams and you hear the characters in the Arcade at the time talk in shock about it."

Secrets with multiple ways to achieve:
1a. The first way to unlock the achievement "Found the Inner Rotunda": "When searching for Pino's bow, take the opposite sewer from where her bow is located. This will lead you to the Inner Rotunda." (Thank you for this, siff!)
1b. The second way to achieve "Found the Inner Rotunda" was found by siff: "Found the Inner Rotunda achievement can be found by taking Beanie's key from the bathroom of the store and using it to get through the employee door." The employee door is basically on the underside of the Combini store.
2a. The first way to unlock the "Got past Dennis" achievement: "Following the Inner Rotundas puzzle path until you reach outside, then ride the water up and jump in the pipe." (Thank you again, siff!)
2b. "After defeating Hephaestus, continuing onward you will see a button, clicking it opens Dennis allowing Dak and Kad to go forward {this unlocks the "Got past Dennis" achievement}. Additionally giving the badge dropped by Hephaestus to either Dak or Kad unlocks hidden dialogue (no achievement)." (Thank you, oz!)

Total Secrets: 15
Secrets found on this guide: 16/15 {??? how did this happen xD)

Before choosing a route (thank you to celestialandromeda for finding this!)
1. "Act two has a secret where after trying to figure out if you're gonna take Kohno's or Albion's route, if you try to head back up the mountain, you encounter a secret where the rest of the passengers/investigators are trying to push the train up the stairs." You have to interact with someone there to unlock this secret and the achievement "The Little Fate Train That Couldn't."

Kohno's Route:
1. Go slightly down Kohno's path, and turn left into a narrow alley until you encounter the Seer. Receive "Branch in the Path" achievement.
2. "When in the Seer's house she will say "grab a seat" {after you give her a mug}. Picking up a chair unlocks a secret" and also the achievement "Grab a Seat". (Thank you oz for the find!) {This can also be unlocked on Albion's route}

Albion's Route:
1 & 2. "act two has a secret where if you take Albion's route, there are humanoid demons. when one spots you and you run away, 3 more spot you and that unlocks a secret {and the achievement "Not that Way"}. Then if you leave the area without hurting them {and then return}, then another secret appears {and the achievement "Okay Maybe that Way": you can either keep going back or change directions again, but make sure to return to the original area}." (Thank you celestialandromeda for finding this!)
3. When you encounter Charon and Pino's lovely performance, they mention the demons don't like light. If you hit the button behind them (either with an object, going around the demons, or going ahead one area and then coming back to hit the button) it unlocks the "They Don't Like Light" achievement.
4. "You can unlock the achievement "OW" in act 2 by attacking Albion's older child {Charon} during the performance after giving combat consent which you can give by pulling something out of your inventory." Thank you T0talZero for finding this! (so mean to Charon *P)
5. "Near the end of Albion's route when you reach the cabin while the two kids are being chased, throw something at the button {or press it yourself} to the right to turn on the lights." This unlocks the "Here Comes the Sun" (do do dodo) achievement (thank you, Wavuvi!)
6. "Inside Albion's home, hop in the pool in the back of the room before speaking to him to get the secret "Took a Dip"." (thank you, siff!)

The Festival area:
1. Follow Solo and pull the valve from the pipe near Beanie and Jesse's store. You'll get the "Found the Combini Spigot" achievement.
2. Keep following Solo and pull the valve in the ninja caves. Unlocks achievement "Spigot in the Ninja Caves".
3. Thank you siff for finding the achievement ""Found the Rice Field Spigot": Go to the Rice Field to the right of the airship crash. Pull the spigot."
4. Go to the festival area (it's the place where you follow Solo to in Kohno's route) and enter the crashed ship. Kill the amalgamate demon to unlock "Beat the Amalgamate Demon" achievement.
5. Killing the amalgamate demon triggers the water cistern to fill, unlocking the "River Healed, Tree in Bloom" achievement. Alternatively, pulling the three spigots will also cause the cistern to fill (thank you siff for finding this!)

Into the seam door:
1. After healing the spirit tree, insist to enter the door. Inside, fill a bucket and throw it at Lepida before Kad and Dakuiri enter. "Proactive Splash" unlocked.
2. Upon boarding Helman's train, hit the blue button next to the save point to vibe to some hi-fi beats B) Unlocks the "Helman's Big Fun Party Mix 5" achievement.

Total Secrets: 7
Secrets found in this guide: 6/7

At Central Station:
1. Find Helman at train 5 and talk to him. Get "Found Helman Cowering" achievement.
2. Give Rocko at train 6 a panda pan (found in act two either a) just right of the savepoint in the town square or b) when you follow Solo, at the vendor stalls). Unlocks "HEEEEERE GLITZ~" achievement.
3. Talk to Stel (he's as far as you can get away from the building) three times and bonk his head as requested to find the secret. Unlocks "-Boink-" achievement.

When imprisoned (go you! *P):
1. After being imprisoned, push both levers toward the back of the room. Unlocks "Unlocked the Cell" achievement.
2. (Thank you for finding this, Vantom253!) "There's a secret when you get imprisoned and use your telekinesis while Lepida sees you." This unlocks the achievement "Confronted about your Telekinesis", and it unlocks when you walk down the hall after you leave the prison, not in it.

At Aurora Station:
1. Put Dakuiri in your inventory and then try to sleep on the couch to trigger the secret/achievement "Tried to Take Dakuiri Home". (Thank you celestialandromeda and Wavuvi!)

Total Secrets: 20
Secrets found in this guide: 20/20

After disembarking:
1. Throw the soccer ball to the folks in the field. You'll get the "Returned the Soccerball" achievement.
2. If you took the heal the spirit tree route (see act two's no route section), go to the river near the playground and talk with Lepida. You'll receive the "Listened to Lepida" achievement.
3. Thank you to Blue Leafeon for finding this!
Tried to Sneak Off... AGAIN achievement: "Rebecca said: It’s if you try to wander off before the band breakup by hopping the fence, and that she may remove it." Guess we better get to it quickly!
4. "When you have to choose to either go left or right {to follow Jellie or Ana}, if you keep changing direction, you will make the bunnies angry and get the achievement "Pick a Side"." (Thank you, brrbrrbatappim!)

Following Jellie's Route:
1. Cut Jellie off by approaching him when he first attacks and then continue going straight down the road (do not chase him here!). You'll move to a new area and he'll run into you. Unlocks "Cut Jelvis Off" achievement.
2. "when Jellie tells you to throw the book at Via, throw the book at Jellie and that unlocks a secret." (Thank you celestialandromeda!) The achievement tied to it is "A Taste of His Own Medicine" (thank you, Wavuvi!)
3. "After Jellie and Ana break up, if you go into the library you'll find Kad and Dakuiri having a tea party with Ana and if you talk to them then that is a secret." You also have to follow Jellie rather than Ana for them to have the tea party. (Thank you celestialandromeda for the help!) The name of the achievement is "Found the Teaparty" (thank you, Wavuvi!)

Following Ana's Route:
1. After Jellie and Ana go their separate ways, chase after Ana and hop over the cars to witness the protest. The achievement "Saw the Human Riot" will unlock. Don't fall into the manhole by accident!
2. ""Put Carrie Back" is an achievement you can get in act 3 while following Ana. If you choose to follow after Ana the first thing you'll do is go into the sewers where you can find Carrie under a waterfall. Just pick her up and then put her back into the waterfall for the achievement. Hope that helps!" Thank you Wavuvi and T0talZero! :D
2. Follow Ana to class. "When you're in class and Calphenor asks you for the best element, pick void. This gives you the achievement "Picked Void"." (Thank you, Vantom253!) You can go back into the classroom after this to unlock the next few achievements/secrets :)
3. Follow Ana to class. After dismissal (or "expulsion" xD), get on the ferris wheel at the back of the class. Unlocks "Rode the Ferris Wheel" achievement.
4. After riding the ferris wheel, ride the slide. Unlocks "Found Slide Party" achievement.
5. After riding the slide, go to the end of the hall and hop on the red slide. At the bottom, keep going forward until you run into the bullies. You can mess with them >:) and also! get the achievement "Found Bullies Under Basement". It's a win-win!

Around the school:
1. Rocko appears in an alley to the right of where Jellie stands when he first attacks you. Bring him an inaccurate tourist map (found in act two in the spirit tree area as well as during Kohno's route, I believe) to unlock a secret and the achievement "The Search Continues...". This is available by exiting the front of the school on the 1st floor during either Ana's or Jellie's route, according to Wavuvi. Thank you!
2. Talk to Solo while he's hanging out in the window on the second...? floor. Solo must survive act two to find this secret. Unlocks "Solo Survives" achievement. {I don't believe it matters if you take Jellie or Ana's route to find him since he's in a public area.}
3. Talk to Dennis in the cafeteria bathrooms. Unlocks "Found Dennis!" achievement. (Thank you celestialandromeda for the find!)
4. This secret is brought to you by The Bismarck. I've slightly condensed it for length's sake, but if you need more details, their comment is down below!
Requirement: Solo falls to despair. (Albion's Route in Act 2 {or not following Solo in Kohno's route, or maybe also telling Kohno not to listen to him (but I'm not sure about that last one).})
i) Go to Calphenor's class, take the ferris wheel, and go down the slide
ii) Ignore the green pipe, continue down through a red pipe
iii) Continue to an open room and then proceed to the room to the left
iv) Demon Solo will be waiting in a boiler room. Upon his defeat, he will shoot fire up out of the room. (This also unlocks the achievement "Finish Solo". Thank you, Wavuvi!)
v) You will be deposited in the main hall of the school with a blue pillar of fire going all the way to the roof. Walk into it, and it will carry you up to the roof with minor damage. The fire will lift the glass ceiling slightly, providing a safe platform. Jump onto it.
vi) Ignore Lepida's requests to go back to the school. You will land on one of the warplanes.
"I'll leave the rest for you to discover." -The Bismarck
This path unlocks the achievement "Found the Secret Lift".
5. {I finally figured it out, I didn't realise two of the metal parts were already attached xD} In the main hall and on every level above it is a contraption that can be moved with buttons. There are two metal parts that are attached: earth (on the second floor) and stasis (on the top floor). The rest of the metal parts can be found in these locations:
* Ice: Albion's office
* Fire: cafeteria bathroom, second stall
* Lightning: in the basement in Jellie/Ana's room (go to the ferris wheel, go under, go down the yellow and then red slide (NOTE: if you progress the story too much, the red slide will be consumed by seams), then last door on the right before the open room).
* Void: behind the cafeteria counter
* Push: on the wall between the gym and library hall
* Pull: on the very top floor to the right leaning against a bookshelf
You then have to press the buttons to align the metal parts with the sigil on the floor. The parts will light up when they're correct :)
6 & 7. Thank you to Vantom253 for finding this!
"If you finished the puzzle with the metal elements and this beam comes out of the underground, you can use it to lift to the rooftop. Get on the glass roof and let it lift you up. Lepida will try to stop you, say that you want to keep going that way {I believe this also unlocks "Found the Secret Lift"}. You're now on an airplane with Lepida and the Bunnies. There's a door you can inspect, this gives you the achievement: Flint experimental program.
Keep going and Lepida will fall to despair and a boss fight will start. I refused to fight at all. The other Lepida came and Beta as well. Despair Lepida dies, Omega (The dark space lady) gets captured by Beta, she asks for help, refuse {I tried yes, but it doesn't matter it seems} and Beta offers you a job. Accept and you got the achievement "False Ending".

Total Secrets: 3
Secrets found in this guide: 3/3*

In space:
When you're in space, move to the left until you see Ribbert. Then, move directly towards the camera, away from Earth. You should run into the Seer there and unlock the "Seer in Space" achievement.

Rocko's secret:
Give Rocko forget-me-not flowers. (You can pick these up in the area where the boulder blocks Kohno's path. Don't touch the boulder! Explore around until you find the shrine.) Unlocks "Void Bubble Buddies" achievement (thank you Wavuvi for the correct achievement name :) ).

Beta's confession:
After the dialogue about Lepida's birth, throw an item at the little baby (you monster <3). You'll unlock the "Squished Baby'Pida" achievement.

The end all be all:
"True end. You get this by collecting all elements. This will give you, as it says, the true end. But it will also delete all your progress after you've finished it and you'll start from 0." Terrifying! Thank you Vantom253 for the sacrifice o7

*For some reason my game says I only have two of three secrets for act four despite doing these three secrets (albeit in separate runs). Let me know if one of these isn't actually a secret. Or maybe the Rocko secrets from acts 2-4 have to all be done in the same run? I'm not sure. Or maybe the true end is the final secret...