Let's start with praise. Simple, but pretty fun concept. I loved the mechanic of walking on walls/ceiling with the plopping sounds, very satistying. Also your camera movement was near perfect, zoom out on puzzless and zoom in otherwise, that was really smart. There were nice puzzles, they weren't too dificult, but were fun to do. The graphics has it's own charm, it looks really cool, even if its made by hand.
On the other side I had 3 big problems.
First being no menu, when the game started, I didn't know what was happening. Was the menu loading, was my game actually bugged since I couldn't not move, I couldn't tell. At least black screen with START button would have been enough. Same with ending, just playing an animation or something would be fine, right now it looks that the game just crashes.
Second problem being no reset/restart button. There were 3 occasions where i got stuck, I managed to get out twice, but once I had to reset whole game and play from the beggining.
Third problem is no background sound. I've had my share of making games without sound and I've learned that without it game doesn't feel completed. Just some ambient sound would be more that enough.
Overall game is quite fun and it has potentional, but right now it lacks some challenge and some other stuff, that would make it a completed game.