The basic setup of the game is that how you allocate stat points into different fighting styles designates how your character acts in cut scenes, and how you will need to proceed through the game, while a person who exceeds in stealth can engage the enemy in hand to hand combat he will most likely fail. There is nearly no actual use of guns and is more of a FPB (first person brawler) there are four types of fighting styles, each of which increases set stats. For example putting one point in the fist fighting style will increase your health by a set amount, your defense and your attack, where as putting that same point into the stealth style will increase your sneaking ability and intelligence (which serves to point out things in a room such as an air vent or other item that can be used since the stealth guys don't get any real attack buffs)
The four styles are Melee (physical attacker who gets major buffs to attack and defense)
Stealth (sneaky spy type prick who can find ways around the enemy without alerting them, comes with stealth kills)
Counter strike (major boosts to speed and minor to defense and intellect, rushes opponents and uses their weapon against them ala Escape from Butcher Bay style)
and my personal favorite the Wild Card (uses grapples and incredible speed to snatch opponents mid run and grind their faces against walls/throw them off cliffs)
There are boss fights but every boss can be defeated in only a few hits assuming you use your style correctly. Example, a physical character would grab hold of the beam on the ceiling, tear it off and impale a mech from a distance, where as a stealth agent would activate an airlock and suck it into space. The game is all about face paced action with most styles and there are wall runs, and other types of cool shit at your disposal.
I've been planing this game for two years now, I even have a large part of the plot figured out and a sequel planed.