Really fun idea! Using the mouse wheel to rev the chainsaw is a super clever way to use the jam theme, and it made the game feel unique right away. I also liked the art style, it has a nice cardboard/cutout feel, and the minimap was a cool touch.
The main things I’d improve are polish and feedback. Some clearer hit animations, louder chainsaw sounds, enemy attack sounds, better UI, and fullscreen support would make a big difference. The scroll mechanic can also get a little tiring after a while, but the core idea is really strong. Great work overall!