Thank you for your feedback! As for getting stuck on the stairs, you can move the mouse to get out (sometimes the character gets stuck by a pixel or two ; changing the camera angle fixes that). Yeah, I understand your point about the environment and download size; I didn't realize that until when I finished the game build (I rarely use pre-made assets so I never thought about this being an issue), I didn't have time to search for a different environment at that point (I barely managed to submit before the time limit).
I will be careful next time, thanks again for playing and I am glad you liked the idea of riddles!