needs a manual
it really needs some ingame-help. What's adrenaline, what are those three coloured bars on the bottom right, why does my special sometimes work and sometimes not, how does the combo system work, ..? Oh, and how do I unlock the other two ships?
sure, I can get through the levels just fine (on medium difficulty, that is), but I can't help feeling I'm playing below my potential without knowing the game mechanics.
other than that, great game.