The game's single player campaign follows a dead man in Purgatory who is offered a deal to defeat the invading forces of Lucifer's army in exchange for being allowed to enter Heaven.

The game was particularly well-received for its multiplayer experience and was featured for two seasons on the Cyberathlete Professional League's World Tour.

The game is inspired by first-person shooters such as Quake, Doom and Serious Sam, with the emphasis on killing large numbers of monsters.

Fighting monsters often occurs in mass battles, where the player has to fight an attack by a swarm of enemies in a large room, while the exits shut and heavy metal music plays in the background, and after such a battle, the player passes a "checkpoint" which advances the game, the exits open up again, and the music returns to the usual softer tune played in the level.

The game presents an option to complete a special task each level, which results in the player getting a "tarot card", a rare, hard-to-obtain bonus.

Each equipped card provides different bonuses for a small amount of time (30 seconds), like powered-up weapons or slow motion.

The game revolves around a young man named Daniel Garner (Cam Clarke), who is happily married to his wife Catherine (Vanessa Marshall).

As they drive towards their destination at high speed, in the pouring rain, Daniel takes his eyes off the road to look at his wife and while his attention is diverted, he ploughs their car into a truck.

With the forces of Hell seizing and corrupting various parts of Purgatory, Daniel goes through different and random phases of history within Purgatory, which range greatly from ancient times to the modern era, including Medieval Europe, Babylon, the Crusades, the 1800s, and a time slice of modern industry.

After killing the first general, Daniel meets a woman named Eve (also voiced by Marshall), another soul who has been in Purgatory for a long time.

After the second general's defeat and reuniting with Eve, Daniel travels to meet a demonic friend named Asmodeus (Jim Ward), for information about new rallying positions for Lucifer's armies.

Eve is wary of Asmodeus and questions as to why he did not finish off Daniel when he was weak, but he insists that he did not come to Purgatory to fill the graves with lost souls like the others.

After Daniel kills Alastor, Eve arrives at the scene in shock, realizing Lucifer will no doubt be on his way and they should make themselves ready.

Suddenly, both Eve and Daniel find Asmodeus highly suspicious and try questioning him as to why he is really in Purgatory, to which he eventually replies, "I dig graves".

He mocks Daniel while recognizing him as a worthy opponent and thanking him for removing Alastor, who had been constantly arguing with Lucifer that the armies should have attacked sooner rather than wait.

After vanquishing enough souls of the damned, most of which are recognizable as foes he has defeated, he confronts Lucifer in Demon Mode and kills him, rescuing Eve in the process, who has been rendered unconscious.

Before confronting his powerful enemy, Daniel visits such places as an orphanage full of possessed children, a hellish circus named Loony Park, a pirate bay, coliseums, Necropolis, and even a twisted version of World War II Leningrad.

Originally being developed by Mindware from the Czech Republic as a fan-made game mod, DreamCatcher Interactive granted the project full financial and technical support.

The death of Hell's leader allows Belial, the prisoner and outcast, to escape and start his vendetta against those who imprisoned him: demonic beast Cerberus and Samael, an angel who betrayed his own kind.

[4] It features six new levels, and a new hero: William "Bill" Sherman, who is blown to pieces by his own C-4 payload, with which he wanted to eliminate a group of mobsters.

However, he wakes up in purgatory and is tasked with redeeming his soul by battling a new demonic threat, which is revealed to be led by Astaroth, once a general of Lucifer, and Ramiel, a corrupted angel.

Similar to Overdose, the new expansion pack was originally a mod, created by a small group of fans under the label "Eggtooth'".

The development team has released free post-release support for the game, which includes extra content for multiplayer, or a new single-player chapter.

The game is narrated through animated text messages, and starts when Belial, the hero of Painkiller: Overdose, saves Daniel Garner from Eve, the current queen of Hell.

Together, Daniel and Belial fight a big battle through her minions in Purgatory, until they have found Bill Sherman, the protagonist of Painkiller: Resurrection.

The game ends with the surprising arrival of Samael, an angel of God who once tasked Daniel with destroying Hell's leaders.

However, the fallen angel Samael (now wingless after his defeat at the hands of Belial in Overdose), who took the power of Hell from Eve, steals Bill's sword and sends him to Purgatory's unexplored locations, forcing the fight to start again.

[9] However while IGN noted the gameplay positively, they also mentioned repetition in certain stages going on to say "simple aiming exercises seem to lack a little substance when compared to more recent shooters".

GameZone praised Overdose for retaining the basic gameplay elements that made the original 2004 title popular, and that it "extends the world with new weapons, enemies, bosses, and levels that will fulfill any adrenaline junkie's craving".

[31] GameSpot however were still annoyed by the long load times and unhappy with the quiet multiplayer mode but were still positive over the gameplay concluding" this old-fashioned shooter is a welcome respite from the scripted, story-driven epics littering the FPS landscape these days (and a pleasant reminder of the simple joy of shooting fiendish creeps in the face)".