Looking forward to the full version
This game seems like a piece of gaming gold, well at least the finished result would. Here's some tips for the game so far.
1) Try to make the game scroll a little earlier otherwise you won't see the enimies coming up later in the level.
2) For some reason the bullets only harm the enimies when your a short distance away, try fixing that along the way of programming the game.
3) The last of them, try to make the frame rate less choppy.
P.S I don't know what you are using to make this game, so if I have said anything in my tips that you don't know how to do well...
Just good luck making the rest.....(: