This is was a fun time! The unexpected use of the tiny theme was a great way to use it and the subsequent boss battle at the end was unexpected and, for me, a bit challenging.
For a gameplay critique, the wall jumping and sliding felt well implemented and good to use, but I didn't feel like I had a lot of control while actually in the air. For instance, if you jump one way, your momentum carries you that way and it takes a second to reverse that momentum. Jumping in one direction and double jumping back the other direction doesn't immediately let you go back. I ended up falling into the water several times from this strange feeling momentum. I think I would have liked snappier air strafing and controls especially when it came to the water platforming bits.