The first level was the most interesting to me, but gosh heck, this could use a lot of spit-shining, and wax, and maybe some duct tape.
I know people are trying to be nice and constructive, but I expected quite a bit more when looking at the other comments.
The shooting; considering this is a mostly shooter oriented game could've been a lot better. You're forcing the player to click a lot, and it wasn't delayed at all, allowing for macros. There's a lot of tutorials out there that can help you make this much better.
The level graphics were too plain and inconsistent.
While the level selection world is always a nice touch, there were only 2 levels, perhaps time should've been spent on a third instead.
As for the theme. It only really shined in level 1, perhaps it would've been a good idea to expand upon that.