Hey! You guys stole my idea!
Jokes aside, its nice to see that somebody else shares the same idea as me for this game jam. Personally, I think that this game would benefit from a bit more gimmicks besides blocks that reveal or hide themselves when masked, because you can only make so many level variations with 2 mechanics which makes the game monotonous. Despite that, the levels were still well-designed and the masking mechanic was smoothly integrated within the gameplay.
Also, not sure if this is intended, but sometimes I could lift up the mask over blue tiles while the player character is on it to instantly push me to the top. I think there's room to explore the interactions between player and masked/unmasked tiles, like perhaps you could push the player with tiles to launch them in a certain direction.