Eidos has said its Missing Link DLC for Deus Ex: Human Revolution, which is expected to last around the five hour mark, includes a new boss fight made entirely in-house.
The announcement comes after it was revealed this week that the bosses in the core game were created by Grip Entertainment instead of Eidos.
"We have a boss battle at the end, but it's different from the main game boss battles," the DLC's producer Marc-Andre Dufort told Eurogamer.
"You can actually not kill the boss. You can do a non lethal takedown on him. And you can kill him from afar. You can even kill him without him seeing you. It's more of a bigger challenge than a standard boss fight like we have in many games.
"Everything was done in Montreal at Eidos. It's a lot less frustrating. But it depends on the way you play. If you played more combat in the main game, you probably didn't have any trouble dealing with the boss fights. So we allow the adaptation of the way you play for that particular boss fight."
Dufort said he understood why some found the boss fights in the main game a bit hard, or sometimes frustrating depending on the playstyle.
"I was playing more of mixed stealth and combat style, so I had some good weapons in my inventory," he said. "I didn't have a lot of trouble dealing with. No, I didn't get any big frustrations dealing with them. But I can understand people playing more stealth style having some frustration dealing with those bosses."
The Missing Link will be made available in October on PC, PS3, Xbox 360, Steam, and OnLive.