Being able to play with 10 lives was a nice option, almost like an easy mode.
I really liked the graphics. They look pretty different from most entries, almost like the characters were drawn with crayons somehow. It also felt like something that could have been on a real Game Boy.
The music got a bit repetitive and could use a few more bars, and one-hit deaths felt a little rough. A simple health system might help there.
Really liked the art style overall!