What I liked:
- the controls
- the jump (That's rare)
- the splash screen having a blurred version of the title screen in the background
- the art and especially the background
- the way how you introduce new mechanics every level
What I didn't like:
- That the "portal" that transports you into next player looks like a player. I got confused by it in the 2nd level -> fix: Use a different shape for example a sphere as "portal".
- the lack of sound effects -> fix: Add "walk", "switch to AI" and "open door" sound effects