Here is the full list of all 43 Marvel Avengers: Battle for Earth achievements worth 1,000 gamerscore.
You unlocked the highest Rank.
You performed a 4x Combo in CO-OP.
You chained 4 Super Attacks by switching characters twice.
You chained 3 Super Attacks by switching characters twice.
You finished all character's challenge.
You won a battle with Wolverine & Magneto.
You won a battle with Super Skrull & Doctor Doom.
You won a battle with Doctor Doom & Doctor Strange.
You won a battle with Phoenix & Human Torch.
You won a battle with Thor & Storm.
You won a battle with Scarlet Witch & Storm.
You won a battle with Super-Skrull and Veranke.
You finished the Campaign mode.
You won a battle with Spider-Man & Venom.
You won a battle with Thor and Loki.
You won a battle with Wolverine and Phoenix.
You won a battle with Human Torch & Iceman.
You finished the first part of the Campaign.
You won a fight without being hit in Campaign.
You won a fight without changing characters in Campaign.
You won a battle with Hulk & Iron Man.
You won a match without dodging in Campaign.
You won your first battle in Campaign.
You got 100 000 Experience points.
You fired projectiles during the ULTRA attack in CO-OP.
You finished the Tutorial challenges.
You won a Tournament.
You won a battle with Hawkeye & Black Widow.
You won a battle in CO-OP.
You changed the costume of one of your character.
You won the arcade mode once.
You won a battle with Captain America and Iron Man.
You obtained an adamantium grade.
You chained two Super Attacks by switching characters.
You reached the FAST velocity when doing a Super Attack 5 times in a row.
You chained two Super Attacks.
You performed a Counter Kick.
You used your Breaker to break a Combo.
You dodged a Super Attack.
You countered a Super Attack with another Super Attack.
You used your ULTRA Attack.
You performed a Close-Combat.
Finish every Trial.