First off, you get NO training or helpful slow mission. You're tossed right into things. So expect to die a few times on the first mission as you figure out which buttons do what and how everything works. It's just part of life in this game.

You start out driving in a timed car chase. Not very nice. And your only clues about which way to go are your turn signals. If you knock them out, you have no hope. Get used to it. Your car is heavy physics, a few hits and it goes up in flames. You're driving on the left side of the road and have English markings on the roads and sidewalks. Really the only thing to watch for is the traffic lights and the cops. The cops are VERY touchy and will come after you if you are even slightly out of line.

Combat is relatively straightforward and has some very cool 'shoot around door edges' technology. Bodies roll down stairs, when you're shot in the leg, your leg has a red spot on it. However you have NO health bar, no way of telling how hurt you are besides watching red spots on your body. And you take VERY few hits before you go down. The way you heal is to lean against a wall. Strange but true. I think finding a medkit in the bathroom makes more sense, myself.

Note that as you pass over weapons, it enables the 'most powerful' weapon in this order.

pistol
picking up 2nd gives you double. Need to reload them - if run out of ammo, you go back to single pistol. can go down to no pistols if you run out of ammo. Very good weapon. Good and accurate with them. Good range.

shotguns
short range. can kill multiple people at close range. It needs to be reloaded. If you drop one it might disappear. In some missions and areas you can pick it up again.

ak47 rifle
good power and range. good when far away and can aim it with R2 button. when you're out of ammo you drop them (cursing)

submachine guns
You can wield 2. When yo'ure out of ammo you drop them.

The Getaway Walkthrough