Not bad
It's entertaining enough, but it seems pretty standard for these types of games. They appear to be everywhere now. Not to discredit all the work you clearly did. I like the upgrade system and such. Seems like it needs some story, or maybe just not stick people. I'm kind of tired of stick people, and you seem to have the talent to do so much more. The main character could be an actual character, and have a story as to why he's defending everything so you could feel attached to him as a person. Instead of a stick.
Anyway, keep at it. Like I said, it was good, and well done. Just needs more style, I think. :)