DIE HARD. IN SPAAAACE.
Starts with a rude awakening from cryosleep due to electrical malfunction, as you try and figure out what exactly happened, you hear voices from the hallway. There are Pirates/Terrorists/Mercenaries. They are looking for something. You grab the nearest metal pipe and start smashing their faces off.
The game is not heavily gun-based, as stealth is a large portion of your survival (you are a young woman, akin to Alex or Chell, not some muscle-clad refrigerator with a head). Guns are less useful, they are harder to aim, have less ammunition available, risk hitting equipment on the spacecraft (or depressurization), and are LOUD (a shot fired inside of a giant metal can will alert EVERYONE to that shot, so plan on hiding a lot if you really have to shoot someone. There would be a silenced weapon, but the extent of its silencing only hides the shots past the first door, and it's subsonic ammunition cannot penetrate body armor, which is fairly abundant among the mercs).
A good percent of the game would take place in zero g, allowing some more fun mechanics. There are three main controls: gripping, kicking, and using your item. You grip onto walls and handles; kick to thrust yourself around; and hit people with heavy pipes, sending a lovely splash of blood and teeth flying towards the far wall.
There would be as little HUD as possible, using an inventory of simply looking down at all your lovely pockets. A glance will tell you what you have, and your hands equip what you want. This includes more than just weapons; as to replace the HUD are manual items, such as a folded up ship-map, pen and paper, pocketwatch, medical monitor, etc. The idea here is to create a more visceral game experience, one with weight and impact, not some magical heads-up-display that says what you need all the time.
The game is to be brutal and up-front. Pull no punches, but not be excessive. It is what it is, not some twisted exaggeration. There is no hand-holding; at most a gentle kick in the pants at the start, just to get you going. The story is as YOU find it. You can just kill the baddies and fix the cryosleep for a quick shot of end credits, or you can find what they're looking for, delve into your past and the purpose of this voyage, what lies have been told and people ripped off. What you try and do, you will do. You could, if wanted, throw a wrench into the main reactor and blow the whole thing to pieces, if that ends your story for you.