When the character is inside a wall, they will start moving up (jumping will make you rise slower.) Holding a movement key will make the character move in the opposite direction.

Getting inside a wall -

Using elevators: Stand inside the elevator Pause the game Press up to start the elevator Unpause the game Spam jump, and hold the opposite direction of where you want to go When you are fully inside the wall, you can stop jumping.

Using text boxes: Stand in-front of a statue or runestone Pause the game Press up Unpause the game Close the text box

The length of time between unpausing and exiting the text box changes how far you get put underground.

It is also possible to get inside a wall by letting a block fall on your head, or in specific places where the camera locks into place (such as the end of the autoscroller/miniboss in the Underground Temple.)

Useful zips -

In the Underground Temple, the elevator can be used to glitch into a dev/debug room. This room has the best sword and armor in the game, and the dash/glide upgrades.

In the Frozen Mines, the elevator can be used to get into another dev/debug room which has weapon ammo, and health. Walking right will warp you to the room before the boss. (This might only work on veteran mode because the last puzzle is a different room.)

In Dark Forest-1, the fire walk with me puzzle can be skipped by using the text box to zip down.

In Dark Forest-2, on veteran mode the statue can be used to skip the miniboss and the first half of the area. (In normal mode, this miniboss has the underwater breathing upgrade, but in veteran mode, it has a key.)

Underground Temple - Here is an another way into the dev/debug room.

Dark Forest 2 - It is possible to get to the area boss without the breathing upgrade by using the statue and runestone. The elevator can be used to get into the room before the miniboss.

A new debug category or glitched category could be made with these awesome glitches great finds!!

Frozen Mines - This is an alternative way of getting the key by going out of bounds. This is around the same speed as going the normal way, but this could avoid unnecessary damage.

When I was messing around with this skip, I somehow despawned the ice bear. Not sure how I did it, but if it is reproducible, this route could be faster.

Aqueducts 2 - I found a way to skip the boat auto-scroller. Use the runestone to get out of bounds, when above the map, double jump over a wall, and fall straight down. When you land, you are in the room after the auto-scroller. Jump right until you can enter the elevator to reset the camera.

This skips the room with the T3 sword upgrade. It is possible to collect the sword and go back to the runestone, but I don't know how fast that would be.

Dark Forest 2 - Using the runstone to zip down instead of to the right looks faster, and it lets you get the bag upgrade without needing to return to this area. There is a spear in the room before the zip which can be used to knock down the block without removing the underwater breathing glitch.

Getting out of bounds from caterpillar autoscroller. Not sure if this is useful

Out of bounds with Gael Castle's teleporter. - Not sure if this is useful.

Dark Forest 1 - Dashing into a text-box zip will make you fly diagonally instead of straight down. This can be used in the Fire Walk WIth Me room to teleport into the heart upgrade.

Underground Temple - Diagonal zip and out of bounds clip from the first tablet straight to the final room. Entire stage completed in about 2 minutes. Skips a heart piece so it'll only be useful to any% glitched

Okay, forget that last post. Here's a better strat that goes through the debug room. The camera can get locked in place at the start of the stage, but when that happens its simple enough to use the audio from the glider to tell that you did the clip right.

Here's a similar skip, but this one is to skip the autoscroller in 100%.

This will change the route for the stage. Instead of going to the debug room first, quitting to map, and coming back to do the rest of the stage inbounds, we'll get the backpack first then go to the debug room and do the skip from there. All together, the stage will look like this:

Takes time spent in Underground Temple from 5.5 minutes down to 4 minutes or less depending on movement (there's about 9 seconds wasted failing to get fully out of bounds in the video).

A few more OOB related glitches:

Out of bounds with the enemies that grab.

Clipping into a wall with a screen transition.

I'm not exactly sure how to reproduce this. I just jumped into a screen transition, paused the game when I hit the ground, then spam jump. The only place where I have gotten this to happen was in Aqueducts 1, between the secret exit and the boat autoscroller. I havn't been able to get it anywhere else.

Glitchy camera when repeatedly dashing into a screen transition

Repeatedly dashing into a screen transition can glitch out the camera. Occasionally Haggis starts rising which might be possible to get out of bounds with, but I havn't been able to do it.

These are a few things I have found, and posted in discord. I'm just posting them in here so they don't get lost.

Devil's Peak - Gliding from double jump upgrade to key room. This skips a puzzle, and the room above the Tier 2 sword.

It is possible to get OOB without a double jump by using a spear. It is also possible to collect the double jump upgrade from OOB by spamming jump on the right side of the screen, and touching the upgrade while inside the wall.

Aqueducts 1 - This is a stupidly hard OOB to do. I'm not exactly sure what starts this, but pausing/mashing jump through this screen transition will put your feet in the ground. It requires constantly mashing extremely fast for a long period of time to do anything useful with.

Gael's Castle - It is possible to get OOB by dying and using the cape after death. Not really sure how to consistently do this, or if it is useful.

Aqueducts 1 - Intro cutscene zip - It is possible to start a zip by pausing on this cutscene trigger. It is quite precise, and you only get 1 attempt. This skips a long room, and can be used to skip the breathing upgrade in any%

Aqueducts 1 - End of autoscroller to boss room by going OOB. Dashing through a screen transition too quickly will glitch out the camera. This makes it possible to jump over the screen transition's trigger.

Gael's Castle - OOB from entrance to water area. Slow fall: When OOB, hold right and glide, eventually you will land in the water section, keep jumping right until the camera snaps back onto the character. Dash jumps: Fall straight down, when you land do a dash glide right. When you land, do another dash jump.

Ledge zip: This is basically the same as a textbox zip, but it goes horizontally. Hang from a ledge that has a textbox on it Press Jump When Haggis moves ontop of the ledge, and moves towards it, pause the game Do the inputs for a regular textbox zip

Flying: For some reason, reading a textbox while hanging on a ledge makes Haggis fly. I haven't found anything useful with this yet