Duke Nukem Forever will reportedly receive at least three packs of downloadable content, bringing new weapons, maps and modes - including karaoke.
Details of the DLC have emerged from files found in Duke Nukem Forever's demo - posted online by egamer.
DLC Pack #1 contains four new weapons - a minigun, a "noob tube", a sticky grenade and a "BFG" - the latter of which was a big plasma weapon found in Doom and Quake.
DLC Pack #2 consists of three new deathmatch maps - "EDF Base", "LKR" and "Map 3", presumably for the game's multiplayer mode.
DLC Pack #3 includes 15 new single-player maps, arm wrestling, the "Impregnader" weapon and a karaoke machine.
This tallies with recent comments made by long-time voice of Duke, Jon St. John: "There will be special add-on packs and features," he said, "including... I don't know if I am allowed to talk about this or not... something that may involve singing. I'll leave it at that."
Duke Nukem Forever's demo is available now to those who pre-ordered the game. It weighs in at a hefty 1.7GB. Pre-order customers also get Duke Nukem's first DLC free.