A game within a game within a game is too complicated.  Not enough time to focus on one game, let alone three.

What if… humans left Earth to explore the galaxy… they stumbled upon hostile aliens… Earth is destroyed (think Titan A.E.), humanity is scattered… relentlessly pursued… by chance, they discover an ancient outpost beneath the surface of a rogue planet… accidentally activate the outpost’s power plant and discover a vast base carved deep into the planet (think the Krell city in Forbidden Planet).  It’s not long before they find devices of great power.  However, their pursuers have been alerted to their activities… and now it’s a race against time to exploit the ancient technology or face total destruction.  Initially, you have meager defenses (only what the humans brought with them, just a few missile launchers and precious few missiles).  As your scientists study the alien technology, they learn to tap its power, unlocking potent weapons.  You must defend the outpost and defeat the aliens by exploiting the outpost’s resources… the key to humanity’s salvation lies… beneath the surface.  Or… yet another Missile Command clone. =)