Not what I expected
I'll be honest. This game is not my cup of tea. I selected it expecting a Defense type game, and what I got was an arcade/shooter. So I feel that maybe one of the problems with this game is that it's not listed in the correct category. When you don't get what you expect, it makes it hard to really appreciate what makes a game unique & different.
Based on what I'm reading, the author is still working hard to this game to make it better. I think that right now, you're off to a good start & have a strong foundation to build on. I wish you the best of luck in your efforts to balance things out & add in some additional features.
Some suggestions:
1) In addition to weapons, can we perhaps have traps/barriers to use as well? That would make this more of a true defense game.
2) Perhaps some ways to upgrade what you have, so that it performs better? If that's already in there & I just didn't play long enough to see it, then nevermind.