So, I'm seeing an exploit: if one doesn't like where an alien spawns, they can just undo to before the spawn. Then when the turn is replayed, the alien spawns are randomly determined again. So the second time, aliens apear in different positions.
Yeah, I was wondering when someone would notice that... Next version (3.1) enemy spawning will use a seeded RNG so it stays consistent when you undo. That's a 2-3 months away though. I'll check how much work it would be to patch for a smaller 3.0.x release.
