GOOD, but survivability is impossible
The idea is great and the game play is solid but there are some things that strike me as odd.. such as when the enemy shoots thorugh a 3 way, it turns into 7 bullets.. and another 3 way makes 14 or something.
also should have continues in it since there isn't an actual scoreboard to post on. Or maybe have 1 ups on the way.
lastly, my personal suggestion, is upgrades... because I do love upgrades in a shooter :D