I enjoyed it, but the screen shake really made it hard to see with the pixel graphics. I see someone already commented on this though and cant wait for an update with that fixed a bit. I think an enemies cap definitely would help the lag calm down a bit, but that could also be because i was playing on the browser version. Reminds me of doom!

Hey this is awesome! A lot of fun! I really like the visual style and the music is great.

A few things I'd might tweak is that the screen shake makes the game almost unplayable if you shoot more that twice in a row, forcing you to wait a second until the shaking stops so you can see what is going on. It seems that it grows stronger with each consecutive shot so maybe turn down the maximum shake amount.

Another thing I might look into is that it's kind of hard to tell when you get hit, the number in the top left changes but nothing else as far as I can tell. Maybe add like an oof sound effect or something when you get hit.

Also maybe increase the jump height, it will make the movement feel a lot more fluid and bouncy.

I would also add a maximum cap to the enemies because after about a minute, the game gets really laggy.

Last thing, make it so the health counter is current health then max health, the way you have it now is backwards and I didn't even realize it was the health counter until I finished playing. 

Again, great start! I love the art and all the issues are pretty minor! Best of luck in the jam :)