Nice game jam entry you have here!
I like the recoil for movement enhancement as game mechanic. Later in the game, where you have spikes everywhere, I fail to execute the necessary key presses on time though .... my finger just won't do it =)
What about diagonal shots? Maybe this could help with all the situations where you would want to move left/right AND keep in the air/jump.
Your first complete game? Wow. I had fun with it!