A Game Mod for Doom II, Batman Doom (obviously) puts you in the shoes of Batman; specifically, the mod's plot is (very) loosely based on the Knightfall storyline. It was released in 1999 by the ACE Team who, years later, went on to make Zeno Clash and Rock Of Ages.
It is available for download here, and is best played with the prBoom source port.
The game is divided into chapters, each of which involves Batman taking on the machinations of a different prominent villain from his Rogues Gallery and eventually facing the villain as a boss.
Batman Doom remains one of the most acclaimed mods for Doom II; among other things; this is due to its Genius Programming, which is apparent to anyone with expertise in Doom editing; while modern source ports give the modders a wide freedom, the original Doom engine is notoriously inflexible, and yet ACE Team have managed to achieve some truly mind-bogglingly difficult tricks with it.
- Action Bomb: The Penguin's walking penguin bombs.
- Amusement Park of Doom: "House of Fear", complete with Creepy Circus Music.
- Bonus Stage: If you manage to finish the first Scarecrow boss fight before a bomb blows up Mayor Kroll, you can access a bonus level. Even this little bit of nonlinearity is impressive in a Doom mod.
- Boss-Only Level: The final level.
- Boss Rush: The two penultimate levels, taking place in the ruined Arkham Asylum, have you facing all the bosses encountered so far, one by one.
- Down the Drain: Shows up very quickly, as your second real level (not counting the Batcave), where you hunt the Killer Croc.
- Fauxlosophic Narration: A few text screens pop up during the game, filled with Batman boasting about how he's the "chosen one" to defeat the great evil in Gotham, or something.
- Fisticuffs Boss: Bane, the end boss. You are forced to pick up a special gauntlet and you cannot switch out of it. If you try to switch out, the fight becomes Unwinnable as you are rendered completely helpless.
- Lost in the Maize: The level with the second Scarecrow boss fight.
- Mind Screw / Joke Level: The Secret Level, called simply "No Comment..." or "Weird!" As the cheesy theme song of the campy 60's show plays in the background, you fight giant flying eyes on a island floating in black void, made out of flesh with trees with half-melted clocks growing out of it, and then enter the (literal) mouth of a meat pyramid to exit the level.
- Molotov Cocktail: Used by the enemy called "Zeke".
- Monster Clown: Evil clowns which toss darts at you, found in the Scarecrow's and Joker's chapters.
- Non-Lethal KO: Technically, all the enemies are knocked out rather than killed, since it's Batman we're talking about - the kill meter is even removed from the stats screen. How can you achieve a Non-Lethal KO with a flamethrower or some exploding barrels is a mystery.
- Outrun the Fireball: The ending of the "Axis Chemicals" level.
- Player Headquarters: The Batcave, which you visit at the beginning of every chapter to replenish your resources a little (and which contains a different secret each time).
- Timed Mission: "Gas Trap", set in a hospital where you have a few minutes to find a button to turn off emitters of poison gas.
- Wolverine Claws: The Cheungs use these.