A game where you are on the evil side.
You start off the game as a grunt soldier, but you work your way up the ranks. You do this by either killing or intimidating those above you. You're given the choice, and the game changes slightly depending on your choices. E.g. Let them live, and you get more help on other missions, but there is a chance they will turn on you (there would be more of an impact in a sequel). But, if you kill them, your soldiers would be more loyal (through fear).
Also at the start, you get a choice of three armours: Light, medium, and heavy. Light armour provides less protection, and your choice of weapons is limited to light guns (pistols and smg), but you're faster and can jump higher, and have a dodge roll move. Heavy gives a lot of protection, and you can use any weapon, but you are incredibly slow and can barely jump, meaning you must take the longest routes. Medium is between the two.
The main goal is to run the evil organisation and rule the country/world/wherever it is.
The main enemy would be something like the U.N., and the main villain/hero would be your best friend who defected to the good side.
Oh, and it'd be an FPS.
And no, you never become good.