Ayyy I like the game'.
The gameplay was fun - the platforming's solid. The jump on the moving block was a bit hard but I got it after a while. Getting the ducking star was REALLY hard; I kept trying to slide off the platform on top into it until I thought about walljumping off that wall. Maybe it could have been more clear how to reach it.
Talking about being clear: I really like the invisible tutorial. The way you go forward to a dead end to then be forced to go backwards, to be in a pit to be forced to jump, etc.
Oh - and fyi, you don't need the ducking star. You can walljump over the wall separating you and the heart.
Gameplay aside the graphics were REALLY nice however I'm taking away points for taking em' online rather than making in the jam. The sound effects were really nice but the constant background noise was pretty ehh'. It did stop when I colllected the heart and it made for a really good atmosphere with the silence and the sound effects.
Overall - really nice! Good job!