Misery: if you're looking at this, I've updated my ships, code simplification and also implemented a suggestion by ptarth. There's a 4th type adding to the 3x3 attackers, which will always come in a pair for hopefully twice the drops. (They should only seed from floor 2 onwards, so there are only two varieties.)
ptarth: I'm thinking a damage multiplier of 0.5 would be more consistent than 0.0, players will then only be damaged for 1, not 2 when leaping over the white bullets.
Please unzip as before - this version is current as of 0.960.