Making a successful PC first-person shooter is getting tougher and tougher these days. While the core game elements, which include running around a level and using an arsenal of weapons to blast your enemies from a first-person perspective, haven't changed much over the years, pretty much everything else has. Recent first-person shooters have begun to emphasize features like realism, stealth, and team-based tactics. However, as we've also seen, there's still room for fast-paced arcade-style shooters, like Croteam's Serious Sam. And like that game, developer People Can Fly's upcoming shooter Painkiller will arm you with heavy-duty weapons and pit you against armies of bizarre creatures. However, unlike previous arcade-style shooters, Painkiller will also make extensive use of the Havok 2 physics engine, which models the now-popular graphical technique of "rag-doll" death animations for fallen enemies, as well as featuring realistic environmental object behavior--like presenting boxes and barrels that are capable of actually being tossed around.

In Painkiller you're an average guy, except that you're dead, you're in purgatory, and you're being attacked by about a zillion demons.

Painkiller also has an unusual premise. You play the game as an ordinary guy who has led a decent life. Suddenly you perish and are sent off to purgatory (rather than heaven, as you seem to have deserved). While in purgatory, you're assaulted by armies of demonic minions, and, by defeating them, you can collect their souls to temporarily become a raging demon yourself. That may sound far-fetched, but the game also lets you pull off some impressive-looking and satisfying maneuvers, like blasting through walls and sending enemies hurtling end-over-end from clean shots from the game's bizarre weapons, like the stakegun. The game is currently in a beta-testing phase and is scheduled for release in 2004. For more information on this unusual shooter, we sat down with project leader Adrian Chmielarz.

GameSpot: Could you explain what aspects of the game the team is currently working on? How is the beta going?

Adrian Chmielarz: Right now, the team is working on the last couple of solo levels--populating them with monsters and objects. They're also working on the multiplayer component. We've had a ton of input on our message boards about what players want to see in multiplayer, and the team is working to integrate as much of that as makes sense--and is possible with the time remaining.

The closed beta is ready. We're just going through the list of almost 7,000 applicants(!) to pull out the testers we think can provide the best feedback. We were totally overwhelmed by the response of the community to the closed beta. It's really encouraging and really helps to spur the team on to make the multiplayer all that it can be.

GS: One of the most interesting aspects of Painkiller that we've seen so far is its use of Havok 2 physics. What role does the Havok 2 engine play in the game? Is it just for rag-doll death animations, or does the game use it for other purposes?

AC: Havok is sweet, isn't it? The use of physics in Painkiller is one of the things we're most proud of. It has enabled so much more than death animations. "Physics-based gameplay" is going to be, in my opinion, the next big thing in gaming.

In Painkiller, players and monsters actually physically interact with objects in the world. For example, in the Thor boss level (which we showcased at E3 2003), Thor will actually stomp around the level and knock over the stone pillars. His AI tells him that (a) you'll be crushed by the massive blocks if they fall on you, and (b) you're small, so the blocks will get in your way and make it harder for you to get around.

As ever, the Havok 2 engine is also known for allowing us to utilize the "rag-doll physics" we hear so much about. A great example is our stakegun. Wherever you fire the stake, that's where the pain and death animation will be centered, so you'll see the fiend writhing in agony as it's pinned to the floor, ceiling, or wall.

GS: What other interesting graphical features does Painkiller support? Since Painkiller seems like a very fast-paced first-person shooter, how are you making sure the game will run at a smooth frame rate once it's released?

AC: Painkiller uses all the latest 3D tricks and techniques: vertex and pixel shaders, dot3 bump-mapping, specular lighting, you know the rest. If you've read about a technique being used in another game, chances are it's also being implemented in Painkiller. We also have a couple of our own innovations, be it a trick to improve the frame rate or a new technique for rendering volumetric lights.

How are we pulling it off? The PAIN Engine. It was custom-built to allow for all this great stuff. It's a really fast renderer, and, even at this pre-alpha stage, I run the game at really comfortable frame rates--even at 1024x768 with 4x antialiasing and 16x anisotropic filtering!

GS: Tell us about Painkiller's sound and music. How do they contribute to the game?

AC: I'm a big fan of game sound effects and music. Together with lighting, sound really sets the stage and helps you really get into the game. In our game, there's ambient and battle music. The ambient music is just that. It plays in the background and is tuned to the environment. The ambient music will really help immerse the player into the game world. The battle music kicks in when the action gets frantic. It's much heavier, with a metal-rock edge to it. Of course, you'll be able to turn off the music if you'd like.

All the music in Painkiller is an original score, and it's great stuff. In fact, the snippets of music that we've released through trailers and movies have really been well received. We've had so many requests for it, we're going to be producing a soundtrack CD. The soundtrack will likely be offered as a preorder bonus.