[Suicide Junkie]

A ruins empire!

The ruins of your planet are uncovered by an alien race, but this time, not everything is dead.

You start with all of the ruins techs, including an operational Planetary Shield, and some weapon platforms. On your very first turn your planet is being attacked by an AI (who is fended off due to the platforms, shield and racial ships, but try to make it a big battle)

The survivors of your race awaken, and must rebuild. They start with very little technology, though possibly a few medium/high areas (soft techs, such as psychology, military science, etc)
There are a handful of powerful, no-maintenance multi-racial tech frigates/destroyers at your spaceyard, but your race has lost the racial abilities long ago. (so you can't deconstruct & analyse, except for ship construction tech)

You were discovered by a long range expedition, so you still have some time to secure your system before the aliens show up in force, but when they do, your recovering civilization will still be far behind in normal technology. The few ships leftover from the fall will be your flagships for many years to come.