I was surprised by the amount of content you were able to achieve in the space of the jam, great work! The visual design is cohesive and fun, the arcade style and simple "mouse over to kill" mechanic worked well, the power-ups from killing enemies is a nice addition, and I do really like the implementation of the map as something you're visually progressing along between each level. I agree with William that it'd benefit hugely from more variation, as currently it feels like there's far too many levels that are more of the same, but given what is present in this version it's understandable. If you do keep tinkering at it, I'd love to see the things like: new weapons to unlock as you go; more enemy types introduced at a quicker pace; more variations in level design, maybe including tiles with certain effects; maybe the maps could be slightly larger and the spawn points could be the size of the largest thing they spawn (I accidentally kicked ghosts in the face a lot as I ran above them).