I didn't realize I had to move up to go to the next level, and replayed the first level over and over like 4 times. (I though the map screen was just a pre-level flavor text and that maybe the game was unfinished and just copy+pasted the first level 20 times.)
The first level is painfully slow. Limited bullets combined with the random movement means that the player's best bet is not only to wait for bullets, but also to wait for the enemies to move, lest they move out of the way just as the player is about the shoot. It's tedious.I think the game might have benefited from having auto-aim. There is just too much waiting for me to enjoy this.