I wish the game was longer! I was waiting at the end screen for the next battle only to realize that no next battle is coming :P
Since the game is so short and I had to restart the game each time I wanted to play it'd be nice to skip the intro and not have to wait for each line of text to appear. I am quite confused about the ammo types. I haven't really felt their impact on the battle. It probably had some but I just didn't see any. The battle itself is a bit lacking, I feel like it's a stripped down version of the Pokemon fight system :D You could add some special attacks that change with ammo! Then I'd feel the impact of changing ammo and had a bit more choice during battle. There is a little bug when you kill the alien and it has negative health it actually attacks one more time.
Overall cool art and sounds, pretty fun experience but very short :D