Idea not bad, but...maybe it's just my personal preference, but i think it would have worked better with a stationary player, and a 1hit kill method. Because in the end all games turned out the same: The enemies come, you run away and try to kill the now huddled group of enemies and then you try to escape from the sidelines.
As the other comment noted, a BGM would have been nice, and maybe some more detailed graphics instead of just blocks. And maybe health pickups?