Great job for your first game! 

I feel like music and rewards for being alive a lot of time (like scores or power-ups) would add a lot of value to this game. If you agree with me, you can try to improve on that next time.

Great job on your first game! I didn't really know what the goal was, I would include some kind of tutorial. Should I just avoid the bullets? Should I try to approach the enemy? Remember that other people aren't you, and they don't know all the secrets of the game like you do.

Also, rather don't make installers for your games. It was statistically proven that games with an installer got worse ratings than games with just the executable for the game.