I really enjoyed this one! The difficulty curve felt pretty good and I like the arcade feel of it! Like a few others said, I didn't quite catch-on that I could only move in one direction at first so I was a little confused but I did eventually understand and had a lot of fun once I did. Other than that, you may want to add some telegraphing to the enemies that shoot. I found myself feeling unsure when they were going to fire, or in which direction, at times and loosing lives but other than that, awesome game!