It’s really impressive that the entire game was made by just one person! The game shows a lot of creativity, especially in its art direction and gameplay ideas.
Aside from the collision box issue that others have already mentioned, there are two things I’d like to point out. First, the main character is shown carrying a gun, but it never seems to be used, which feels like a bit of a missed opportunity! Second, unless I missed something, the character doesn’t seem to be able to move left or right. This makes the issue with the game’s scale and screen size a little more noticeable during gameplay.
Overall, though, this is a pretty solid first game, especially for a solo project. I hope you keep making games, and I’m looking forward to seeing what you create next!