Here is the full list of all 19 Saban's Mighty Morphin Power Rangers: Mega Battle achievements worth 1,000 gamerscore.
Win all the Megazord fights.
Defeat all bosses.
Defeat 600 enemies.
Defeat 400 enemies.
Upgrade a technology in the Tech Tree.
Complete the first chapter.
Toss 50 enemies.
Perform 30 Power Kicks!
Reach X10 combo with an air attack!
Complete a level without receiving damage.
Morph with another player at the same time.
Perform Co-op strikes with 2, 3 and 4 players.
Revive a teammate 30 times.
Unlock all the moves of a Ranger.
Maximize a Rangers' technique.
Win a multiplayer boss battle without any character dying.
Max-Upgrade with all the technologies in the entire Tech Tree for all the Rangers.
Complete a chapter without receiving damage.
Reach floor 50 in Rita's Tower.