Not bad for a first attempt...
For a first try, this is not bad. All the basic elements of a game are there at least. Things to consider for the future:
*Sound effects and music. These are pretty vital to a game, and without them, yours kind of felt like a test or preloader game.
*Expansion. The game was pretty linear. There weren't any powerups, but there were a few items to manipulate the game, so it wasn't completely boring.