To parapharse another reviewer, "Its just you, a bunch of guns and the entire population of Murdertown between you and where you want to be."
Seriously, this is a great FPS. Too bad many other FPS cannot duplicate Painkiller's formula. Arena fights, a plethora of distinct enemies, and original weaponry.
The reason the game gets a 9 out of 10 is the cinematics and gameplay issues.
First, the cinematics are really unnecessary. A storyline is for a game like the need to have bubonic plague. The length of the cutscenes rival that of MGS 4. In some cases, the space-time aspect kicks in when you watched a cutscene for 3 minutes, but it feels like 20.
Gameplay issues are minor, but have the feeling that you can cheat the game with out game codes. Enemies in some areas can be locked up on environment and remain there. And when the game is constantly spamming you with enemies, this tactic gets boring after a point. Most areas do not have this problem, but after having your adeneline at its highest peak, only to be able to "point and click" enemies to death in the next area, reduces some of the fun.
For people who remember the original Unreal and Doom, this is the best game for you.