From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
The Time Breakers is an alliance of villains that Miira leads.
Miira recruited members of the Paella Gang, the Red Pants Army, evil Namekians, remnants of Freeza's Force, Bardock, Artificial Humans such as Artificial Human No. 8000 and Artificial Human No. 19000, and evil Majins into his faction to help him in his quest to steal Son Goku's DNA.
When traveling back in time, Miira and the Time Breakers have created temporal distortions in the past, thus it is now possible for people who get sucked in to change the past.
Time Patrol Trunks was forewarned by Dende of Miira's intentions to spread chaos throughout the main timeline. Using a Time Machine, he and the players travel back in time to try and restore the timeline, fighting the Time Breakers in several Time Machine Quests in the game.