Painkiller: Battle Out of Hell

Engine

Painkiller's proprietary 3D engine is called PAIN. The base game uses version 1.0, the expansion has the improved 1.5 version. The physics are handled by the Havoc 2.0 engine, just like Half-Life 2.

German index

On 30 April 2005, both US and European English versions of Painkiller: Battle Out of Hell were put on the infamous German index by the BPjM. For more information about what this means and to see a list of games sharing the same fate, take a look here: BPjS / BPjM indexed games.

German version

All blood and gore effects were removed or replaced with green blood. Also the first level (orphanage) was renamed to a "Herrenhaus" (manor) and the zombie children were replaced with regular demons.

Music

The music heard during the level Leningrad is the national anthem of the USSR.

References

The first level, The Orphanage, is a big shout out to other horror-related games:

• The 7th Guest and The 11th Hour: the first room has a layout just like Mr. Stauf's mansion. The stairwell is pretty much identical as well.
• Grim Fandango: at the top of the stairwell, you'll see a message "In case of Zombies, Call Grim Fandango".
• American McGee's Alice: the library with the massive bookshelves.

Information also contributed by Medicine Man, Scott Monster and Xoleras