Alien Carnage
Trivia
Freeware release
On May 24, 2007 Alien Carnage was released as freeware by 3D Realms with the permission of John Passfield. The game had previously been discontinued from their product line on April 21, 2000 due to it having problems running on Windows. They recommend using DOSBox to run the game on Windows 2000/XP/Vista.
Halloween Harry
Before it was named Alien Carnage, the name of the game was Halloween Harry. The name was supposedly changed so the game would have more appeal all throughout the year rather than just Halloween. The two versions play exactly the same, but Alien Carnage swapped Block 1: Office and Block 3: Sewers, as well as rotating the music for Blocks 1-3 around.
Music
The music in Halloween Harry was done with .mod files, slightly altered to not play in a standard mod player
Release history
This game's first publicly available version as Halloween Harry was version 1.1 released on October 10th 1993. Version 1.0 of the shareware version was an incomplete version released only to a UK magazine.
When the game was released as Alien Carnage, its version 1.0 release was released on November 2nd 1994.
References
The 3rd level boss, a "sentry droid", is labelled THX-1138 -- George Lucas's first movie, made even before Star Wars. (This is a common injoke in the game industry.)
Shareware content
A shareware version of Alien Carnage was released which had "Block 1: Sewers" playable. Halloween Harry's shareware version had "Block 1: Office" playable. Due to this, half the game ended up being released as shareware.
Studio.exe
The game includes a Studio.exe file in its directory (originally included as a bonus for acquiring the full version) which allows to play all the music from the game.
Information also contributed by Scaryfun, Tomer Gabel, WildKard, Xantheous, Yakumo and Zovni.
Trivia contributed by Accatone, Cantillon, Patrick Bregger, piltdown_man, Jo Li KMC.