Game could use some polishing and fine tuning, I like how each enemy has its own type of soul and I wish the game delved more into it by having mechanics revolved around it.

Interesting idea! Wish it got some more polish.

The mechanics were confusing, even with explanation. Probably because there wasn't any visual feedback between the bird and the passcode (or I missed it), so I couldn't tell that the two mechanics are related. I completely missed the moment when I unlocked the first two colors in passcode, and why it happened. Coincidentally, the first 3-color combo I got was red-red-red, so I thought that the resulting change was what's supposed to happen once you collect any full 3-color set.

I think the art was pretty good, you definitely had a consistent style going on with the characters, but their explicitly vector style looked weird against explicitly pixelated terrain.

The game should probably disable fall damage while the cheatcode is active and just limit vertical movement, you get teleported upwards and off-screen and don't fall down, so it looks like the character disappears.

I... didn't like the music choice, it was just a short loop with no variation that got grating after a while.

Anyway, hope my feedback does not discourage you in your future projects, good luck!