Painkiller is an action-driven FPS (first person shooter) game set in a dark and sinister world somewhere between heaven and hell. You take on the role of Daniel Garner, a seemingly regular guy, who has just been killed in a horrific car accident. As you struggle to find the reasons why you've been denied entrance into heaven, you must fight against hordes of demonic soldiers in an attempt to stop an imminent holy war.
- Next-generation graphics: The game uses the proprietary 3D "PAIN Engine" capable of pumping out an unbelievably high polygon count, while adding increased texture quality and the latest lighting and shadowing techniques.
- Combo weapons: All weapons come in pairs, with a primary and secondary fire.
- Morphing: Your unholy pact gives you the power to morph into a powerful possessed creature with every 66 souls collected.
- Lasting replay value: Painkiller features a standard single player campaign, with additional modes to encourage replay. The game also features full multiplayer support.
- Physics Engine: Painkiller employs the Havok 2.0 physics engine, allowing for inverse kinematics ("rag-doll physics") and deformable, interactive environment.