This guide is a collection of as many glitches and exploits in Cat Bird as possible, ignoring their relevance. For the relevant glitches only (with more explanation), see https://www.speedrun.com/cb/guide/w4mn6 for the first four glitches (and Spike Jump) or https://www.speedrun.com/cb_ce/guide/z6kpj for the fifth.

Pause 'n' Play (PnP): Pause the game to manipulate the cycles of moving objects. This likely skips decelleration/accelation phases and thus shortens cycles/reverses directions.

Box Slide: Move into the box while standing on its very corner (significantly easier and more consistent towards the left) to accelerate to a combined pushing and walking speed together with the box.

Forced Transition Pause: Force the game to pause in a level transition (for example by using the notification bar) to stop the in-game timer until the next level, but not the game itself.

Timer Reset Glitch: Use the reset key while exiting the last level of a time trials run to set the timer to a lower value.

Zipsa Skip/Wrong Warp: Watch the Zipsa Entry cutscene for the first time after exiting a level with a level id of your choosing to be transported to the Zipsa level with that level id.

Milk Jump: You can jump off of the floor that is right below the collision check in milk (below the moving part) by being lucky and fast.

Block climbing: You can stand on the very edge of the individual cat blocks of a wall of them to climb them one-by-one

Vertical Teleport/Box Warp: By falling through the same teleporter as a box right after it (by box sliding, for example), the teleporter's x-coordinate is ignored and the cat bird is moved to the y-coordiante of the teleporter exit, but the x-coordinate of the teleporter entrance.

Box Slide Out-of-bounds: You can fall out-of-bounds by box sliding downwards so that only the cat bird, but not the box, is above solid ground, which will simply be ignored, leading to the cat bird landing out-of-bounds.

Box floating: Boxes can fail to crush the player (when they're pushed into the ceiling) if the player is stuck in a glitched fluttering state above them.

Falling Block pushing: Falling blocks can be pushed similar to boxes while they are falling and pushed around afterward by repeatedly running into them. This also allows for falling block jumps (like spike jumps) on the very side of ground below a landed falling block.

Unblocked falling blocks: Falling blocks can fall through one-way platforms that aren't rendered.

Spitball pushing: Spitballs (the creature) can be pushed similarly to landed falling blocks.

Spitball rolling: The arc a spitball (the ball) follows can be forced to be basically a roll by landing on top of it with a falling block, which pushes the ball as far down as possible.

Ghost jumps: Jumps, where the game quits the jump after a single frame. Possible for example on broken versions of cat bird or on falling blocks.

View exit: In levels with sections without side walls it can be posiible to exit the visible part of the level, as there is no camera modifier to be triggered that'd pan the view.

Ad pause glitch: On some devices and versions, the pause the game enters when playing an ad doesn't work correctly and allows the game (and also timer in time trials) to continue normally, just while the pause overlay is active. This false pause changes into an actual pause after a few seconds.

Post death/reload collection: By falling into a key, activating a switch or doing anything else that produces a sound after using the reload key or dying, the sound will still play even though the character should be unable to collect anything.

Box&Spitball lifting: (Possibly intended?) Boxes and Spitballs (the creature) can be pushed up by jumping into them from below.

A lot of these glitches are shown in this video:

Other things:

Sprite errors: The rightmost black pixel in the bottommost lime of the third (and sixth) frame of the black cat bird uses the wrong color (070707 instead of 261d38). [Also there's a set of unused whiskers for Zipsa in the game, but I think those belong to a previous version, as Zipsa is now using the Grasi whiskers as well.]

Display scaling errors: (This is probably a stencyl issue and sometimes fixable by changing notch settings) On devices with a notch, camera hole etc. the game is pushed out of the notch area by the size of the notch, however the game scaling uses the screen area including the notch to scale itself and thus moves an area equal to the notch area out of the screen area (which is often nearly the entire pause button and a lot of the jump button).

Input issues: (Also a stencyl issue, most likely) On some MIUI 12 versions, the game accepts no input at all. This is not the case with MIUI 13.

Please tell me of any other glitches on the discord.