Hmm, that sounds good. it'll work for all the upgrades we'll have for our spaceships. The main problem I'm having though is with laying mines, shooting rockets and lasers. I'd have to have a whole bunch of laser entities... and could only reuse them once they've hit something. Maybe for the laser entities I could just move them on one machine only, but the problem remains with the rockets, which will be visible. The good news is that the player will run out of rockets at some point, meaning that I could just create those once he buys them, and have them sitting somewhere passable and invisible. Same would work for the mines.
Thanks, in case no one finds something else, this should work...

Micha