[KirbyEF]

What about planet based "artifacts". You control the planet you have that ablity or special facility (ancient weapon, processing plant, gateway, research points bonus, etc.).

What about negative effects (find a reactor that makes the sun in the system goes supernova, a plague outbreak, turns the system into a nebula/storm etc.). You can stop most of these negative ruins by applying research to stop the bad effect.

Maybe when you find a ruins you find an ancient race that is upset that you woke them up or distrubed them. That race should be a Non-Player race that will attack anyone, but of course the race that finds it will probably be closest.

KirbyEF