Pure FPS Action
If you enjoy a game like Doom you should love Painkiller. It is basically the same kind of thing except instead of the key-fetch rigmarole you have checkpoints that funnel you through the levels. You're still shooting many, many demons with big guns and running about like mad. You're still able to carry a ridiculous amount of ammo and several large guns that magically don't require reloading but you know what? That's fine. This isn't the kind of game you pick for the realism (save the physics), this is the kind of game you play when you just want to sit down, unwind and unload hefty shotgun blasts into hordes of hell's minions. And it hasn't been this good for a while.
Given this, the main focus of Painkiller is the action; the battles and the guns. However, one can't overlook the addition of physics to the tried and tested FPS formula. Most of the time you'll be admiring the ragdoll system where a rocket blast will send foes flying off in all directions with their limbs flailing about lifelessly till they hit a wall or some similar solid object. The Stakegun, oddly enough a gun that shoots large wooden sticks, is another favourite. For example, you can use it to pin enemies to walls and their limbs will just dangle helplessly as they are stuck up there like some hideous vestige of your marksmanship. Rushing into a huge group of enemies with the shotgun blasting is quite an experience as you plough a path of destruction through a mass of evil.
The level design is sort of a hit and miss. You will get some amazing levels like a monastery/island, an insane asylum and an opera house. On the other hand there are a bunch of factory/industrial/underground levels that all seem pretty much the same and when played consecutively tend to be a bit of a grind. Nonetheless, it succeeds more often than it fails.
The sound and music were quite enjoyable. The weapons all sound understandably powerful, plenty of explosions, enemies shouting out, cries of defeat/anguish- it sounds like a warzone. The music is good too. When you enter a battle the ambient, laid back music changes into some heavy metal to get you all fired up so you can blast through hundreds of soldiers, foaming at the mouth. It does tend to get a bit samey, much like the level design it can sometimes blend together and become a grungy, testosterone-filled mush but it fits the game well and I generally don't have a problem with it.
What I do have a problem with is the game design choices at some points. Like a boss fight near the end of the game where you can be killed by fall damage. I know there are ways to avoid it and I know it's trying to be different to all the boss fights before it but come on, fall damage? The annoying thing is the boss itself wouldn't even be that hard without this aspect. Maybe they just got tired of making models of really, really big enemies.
So is Painkiller just Doom with physics and a better graphics engine? Pretty much, but there are some extra tidbits in there. You can collect cards by meeting certain criteria for each level e.g. Complete level x by collecting y souls. The cards provide enhancements or new skills that make the game easier e.g. more damage, faster movement etc. In order to use the cards you have to spend a certain amount of gold to place them in your inventory (gold is collected in the levels) and you can only place a certain amount. So there is a strategic element there but really it's only on the higher difficulty levels that you'll actually find a need for these cards.
Another feature is the ability to turn into a demon. Each time you kill an enemy, they disappear in a puff of smoke and their soul is left behind. If you collect 66 souls you then turn into a demon that can one-shot-kill any enemy and can move slightly faster. It's more of a "there if you need it" thing once again- if you become skilled enough at the game you won't be bothered with it as much but starting out it can be a bit of fun.
So there it is, Painkiller is basically like a new version of Doom with some added features and ragdoll physics. This doesn't mean it's a bad game though. If you go into it knowing what to expect you will have a massive amount of fun. Just don't expect anything revolutionary. Expect an old-school FPS with action, action and more action... Oh, and big guns.