I was a bit confused at first, but it was quite fun when I got the hang of it.
I don't know if this is intentional, but I experienced a bit of input delay when moving horizontally which made it much more difficult to dodge incoming bullets and jump to smaller platforms. Also in rare cases, I'd land on the ground, press space, and the jump wouldn't get triggered.
I think the enemies' bullets were a bit too small or difficult to see. Maybe a flashing animation for them would do the trick. I'd also appreciate it if the UI buttons and the perks could be controlled with the keyboard since you don't use the mouse for anything else.
The retro sounds were neat and the music fit well with the rest of the game.
A pretty cool entry overall. Good job!