Very cool game! The scarecrows movement was quite spooky and shooting them felt really nice. I do also like the art style route u chose. However, I was missing some kind of a reason for why I'm there, why I'm going through the maze. Even a short story explanation would be nice. Granted, I'm a writer so I'm always looking for those things, but still it would be a nice little addition. Also some sort of music would be nice. Adding UI would also help, how many things did you collect or even what to look for.
Overall nice small game, nice usage of the limitation. Maybe you could make it longer, or add other levels, other guns or even other types of scarecrows. But great job with this one :)