Full list of all 30 Bellator: MMA Onslaught achievements worth 400 gamerscore. It takes around 8-10 hours to unlock all of the achievements on Xbox 360.
Unlock All Technical Skills
Unlock All Submission Skills
Achieve Maximum Level with Custom Fighter
Unlocked All Throw Skills
Won 25 Fights By Submission
Performed 25 Throw KOs
Win 10 Ranked Matches With Boosts
Play a Ranked Match in Every Arena
Won 5 Ranked Matches in a Row
Got S Grade in a Ranked Match
Won a Ranked Match
Defeated Opponent in under 20 Seconds in a Ranked Match
Won a Ranked Match Without Being Hit by a Strike
Won a Ranked Match Without Being Thrown
Won a Ranked Match Without Being Clinched
Won a Ranked Match Without Being Taken to the Ground
Played a Ranked Match
Performed 25 Parries or Counters
Performed 25 Punch KOs
Performed 25 Kick KOs
Unlocked All Striking Skills
Finished Tournament Mode
Applied a Boost
Completed a Challenge
Used The Move Editor
Created Custom Fighter
Played using every official Bellator Fighter
Played a Player Match
Played Tournament Mode
Won a SuperFight Match