Extreme Exorcism begins simply. The first round of play pits players against a possessed piece of furniture in one of several spacious rooms scattered throughout a haunted mansion. The enemy is easily dispatched with one of the many randomly spawned weapons found nearby, and the round concludes with little fanfare.
In round 2, a ghost enters the arena. Several seconds may pass before you figure out that the phantom mirrors your movements during the previous round perfectly, replicating your jumps and attacks in a pre-programmed daze. If you can remember what route you took while you were battling the possessed furniture in round 1, your ghostly doppelganger should pose little challenge.
Round 3 begins. Your ghost from round 1 teams up with a new apparition that replicates your performance from round 2, and you must exorcise them both. Every round afterward adds another ghost to the fray, and it isn't long before you succumb to your previous expertise. This is the essence of Extreme Exorcism, a game in which you are truly your own worst enemy. Super Crate Box, substituting enemy AI with opponents driven by controller input playback. A few additional gameplay wrinkles add complexity; player ghosts enter each round seconds apart, keeping players from easily memorizing the timing behind their doppelgangers' movements, and once a ghost's recorded input ends, it reverses playback, making its movement even more unpredictable.
Tracing its origins back to a simplistic Unity game, Extreme Exorcism has since grown in size and scope, and now includes more than 20 weapon types. Players collect an arsenal that ranges from traditional fare like pistols and shotguns to more powerful attacks like rocket launchers and electrical auras that kill everything within a large radius.
I played both the single-player and multiplayer modes of Extreme Exorcism at PAX Prime, and both felt equally polished while having their own distinct flavor. Single-player modes often get the shaft in multiplayer-focused arena combat games, leaving solo players to compete with easily outwitted AI. This isn't the case with Extreme Exorcism; the single-player mode features its own campaign with varied level layouts, and its subtle shift in gameplay mechanics makes it more than just a novelty.