I enjoyed playing but I wasn't sure if there was an actual end/boss or if it was an infinite game. I got to level 20 with I think 64k points (600 speed, 1.5 bullet speed, and maybe +100 damage?) but then got mobbed on a really bad 2 skull room and lost all but my last life. Then died stupidly in a 1 skull room trying to gain some hearts.
I liked what I played and the shooting felt pretty solid. I might have preferred to feel like I was getting faster or stronger at a quicker pace.
in my next game I tried out the cheat codes and had a really fun time with the shotgun.
Music was great but after several waves it stopped. Maybe it wasn't set to loop?
Theme was a bit weak though :)
Nice game, especially for your first jam.