Okay so when I activated fullscreen, I found out that level 1-11 is literally impossible. Everytime you enter the corridor on the bottom-left, you just get sent back to that corridor.
Yeah, 1-11 is literally glitched, but you can only see it in full screen mode. I dunno what happened between playtesting and posting, but it's glitched now.
When the green box is placed on the button in the top left, the gate sprite disappears, but the hitbox remains.
Edit: You can brute force it by mashing the arrow keys, so technically it's not a problem???