Tons of problems.
1) If you shoot the bad guys more then your suppost to. They come back to life. This is the biggest problem with the game. It makes it unplayable.
2) The enemy design is relly bad. I think it could use more detail.
3) Theres no story what-so-ever. The whole thing seems pointless. Just shoot the circles with faces. Trust me, a simple story and background of the main charater could make a huge difference.
I'm sorry to be so rough. I'm not trying to be mean. I understand that this is your first video game. And it might not be perfect. But there are alot of things that need improvment befor it can be released to the public.