I know its not fair but
You really have to use your first level to hook new players in.
And it didn't do it for me. I only got as far as the first level, which was slow and dull and unexciting. Scrolling shooters should be fast and difficult, man, not slow and plodding. If I'm not dodging a million projectiles and trying desperately to shoot back, then it's not a good shoot em up game, and this wasn't a good shoot em up game.