Gears of War: Ultimate Edition, announced at E3, is a major reworking of the first Gears game, replacing art assets, tweaking gameplay mechanics and generally adding a lot of new stuff to a game that's now 10 years old. But one addition that won't be coming to Ultimate Edition is the Gears series' popular Horde Mode.

At a panel at San Diego Comic-Con, Gears of War co-creator and studio head of developer The Coalition Rod Fergusson confirmed that Horde Mode will not be part of Gears of War: Ultimate Edition. He went on to list several major reasons for this decision, including the fact that the developer didn't want to turn Gears of War into one of its sequels, even if it took some gameplay elements from them.

"We didn't want it to creep too much into Gears of War 2 territory," Fergusson said.

Fergusson went on to explain one of the reasons Horde Mode was added to Gears of War 2 in the first place: The sequel also included a huge number of new enemy types. Without such variety of enemies to take on in the first game, Horde Mode would feel very limited by comparison.

Gears of War: Ultimate Edition will still include some additions made popular in later Gears games. For example, Fergusson said that spotting enemies in multiplayer mode, a mechanic added in Gears of War 3, will make its way to Ultimate Edition.

"It reinforces team play in the multiplayer modes," Fergusson said.

Gears of War: Ultimate Edition will be released for Xbox One on Aug. 25 and will include access to a Gears of War 4 beta sometime in 2016. A PC version of Ultimate Edition has been announced, but no release date has been confirmed.