Nice first try, the enemy sprites were very cute and the character is cool looking. I found the controls a little bit stuff, especially the jumping. Would be good to see a bit of a faster fall and I encountered an issue where the gun is only shooting in the opposite direction from where I'm facing, an easy fix!
You could try and get some consistency with the art as well so either using outlines all the time or not at all, I'd like to see little broccoli with an outline for example.
I also ended up getting stuck after falling and I didnt "die" but couldn't do anything else.
Stick with it though and I'm sure with a bit of polish it can become something great one day!
Good job :)