I want a universal simulator game, with Aurora levels of detail, with civilisations rising and falling and warring and loving and doing all sorts of cool, simulated shit. The player's only real function, is to press the reset button at the centre of the universe, which will wipe out all organic life and leave every planet, machine, and star intact, allowing for new life to rise again. New species and new cycles of civilisations will grow, and be influenced by the wrecks and husks and dead planets left by beings that clearly existed, but no longer do.
As your game goes on, each cycle of the universe starts learning faster and faster as more and more evidence piles up that SOMETHING wiped out life on planet after planet, over and over again. You can't press the reset button continuously, you have a cool down of say, 100 million years. If a civilisation manages to reach the centre and dismantles your Universe-Cleanser device before you can re-press the Reset button, you LOSE/WIN, depending on how you look at it.
In the interim period, the "cleansed" period of the universe where your existence scanning capabilities detect no life, the game turns into a bit of a god simulator, allowing you to reshape planets, star systems, reallocate resources to ensure certain sorts of life grow here and not there, that sort of stuff, all in preparation for the next cycle. Do this while there's intelligent running around, and your chances of being discovered as the puppet master behind reality rises drastically.
Sentient AI machine-life would be interesting in this game, as you would have no direct way to destroy them, but to balance that out, most organic life develops very strong prejudices against synthetic life, causing wars to erupt between the two states of life constantly. So, if your really want to strategise, you would encourage as much organic life to exist as possible, to war against and wipe out the less expansionistic and slower reproducing machines.