A polished Space Western with the Metroid Prime scanning system integrated into your monocle along with ammo, HUD and shield energy (health). Other things:
-An energy conversion module that allows you to turn shield energy into energy for your futuristic guns whenever you want, and vice versa.
-Conversely, there is no regenerating health. You only regain your energy (for both weapons and shields) at checkpoints. This prevents 'But I Might Need It Later' syndrome for your big guns, and leaves no excuse not to throw armies of brutal alien monsters at you in every single leg of the game.
-Your opponents are a group of infamous bandits (including cyborgs and aliens) with Metal Gear-esque quirks, powers and backgrounds. When you're in the final stretch leading up to them, they will be taunting you as well as revealing their backstory instead of in cutscenes like MGS.
-Your own characters monologue is also delivered while in action like in Prince of Persia.
-Possibly open world with hovercraft provided for travel across the swathe of desert dividing the major locations. You have your choice of being the driver or the gunner, which is important when the desert beasts start to chase your craft (becoming more and more powerful/aggressive as the game progresses).
Could be more innovative sure, but I'd rather just see a new really well-executed single-player focused FPS than anything revolutionary, and after seeing the Unskippable for Starhawk that's what I imagined the game to be like.