Alien Carnage, originally called Halloween Harry, is a side-scrolling platform game developed by Interactive Binary Illusions and SubZero Software, and distributed by Apogee Software. The game features 256 colour VGA graphics and background music in MOD format. Alien Carnage is composed of four episodes. The first episode was released as shareware, and the rest were distributed commercially. In May 2007, John Passfield and 3D Realms released Alien Carnage as freeware.
The cartoon-style game features agent Halloween Harry, who has to save the world from aliens that want to take over control of Earth by turning its population into green-skinned zombies. Some of the enemies reference Aliens, Gremlins, and Elvis Presley. Harry is helped by controller Diane, who gives him information via a video link.
In the game, the player has to shoot zombies and aliens with his flamethrower and other weapons, rescuing hostages along the way. Instead of jumping, Harry uses a jetpack to reach higher platforms. His jetpack shares ammo with his flamethrower, which means it is best for the player to use both sparingly.
Harry can eat and drink junk food to gain health (rescuing hostages also restores Harry to full health), and upgrade to different kinds of ammo by using ammo dispensers. The player needs to collect coins dropped by killed enemies to buy this ammo. They can also pick up other power-ups with various effects, including a wrapped gift (additional ammo for Harry's current weapon), a money bag (30 additional credits; coins dropped by enemies are worth 5 credits each), and a 1-up icon (an extra life, plus full health).
The game progress can be saved through the use of computer terminals scattered across the levels. To advance to the next level, Harry needs to rescue all the hostages, then use the elevator.
In 1996 a sequel called Zombie Wars was released. In this game, which takes place three years after the original story, the aliens return to Earth to try to enslave its population. Harry and Diane, who has been promoted to field agent and is now also a playable character, have to save the world again. A number of other friendly characters have been added as NPCs.
4 different online emulators are available for Alien Carnage (Halloween Harry). These emulators differ not only in the technology they use to emulate old games, but also in support of various game controllers, multiplayer mode, mobile phone touchscreen, emulation speed, absence or presence of embedded ads and in many other parameters. For
maximum gaming enjoyment, it's important to choose the right emulator, because on each PC and in different Internet browsers, the individual emulators behave differently. The basic
features of each emulator available for this game Alien Carnage (Halloween Harry) are summarized in the following table: