This is kind of a cool concept. It's like Space Golfing.
Another alternative is to make it like a turn-based Scorched Earth (Mother of all games), where you can either
1. launch asteroid size projectiles across star systems in a field of stars and black holes to it each other.
2. launch projectiles that then place black holes (perhaps either by timeout or signal--taking into account the speed of light!) to change the field.
It's a good start!