Here is the full list of all 30 Marvel vs. Capcom Origins achievements worth 400 gamerscore.
Finish arcade mode with each Marvel character (Marvel vs. Capcom)
Complete the third tier of the challenge “Grinder"
Win a match with every character (Marvel vs. Capcom)
Finish arcade mode with each Capcom character (Marvel vs. Capcom)
Finish arcade mode with each Hidden character (Marvel vs. Capcom)
Finish arcade mode with each hero (Marvel Super Heroes)
Finish arcade mode with each villain (Marvel Super Heroes)
Complete the third tier of the challenge “War of the Gems" (Marvel Super Heroes)
Finish arcade mode without losing a round (Marvel vs. Capcom)
Finish arcade mode (Marvel vs. Capcom)
Complete the fourth tier of the challenge “Big Finish”
Complete the third tier of the challenge “Powers Combined" (Marvel vs. Capcom)
Complete the first tier of the challenge “Uatu the Watcher"
Complete the third tier of the challenge “Hyper Artist"
Complete the second tier of the challenge “Looking Cross"
Complete the third tier of the challenge “Duo of Heroes" (Marvel vs. Capcom)
Complete the third tier of the challenge “Another Notch”
Complete the second tier of the challenge “Aerial Rave"
Complete the third tier of the challenge “Hip Tosser"
Finish arcade mode without losing a round (Marvel Super Heroes)
Finish arcade mode (Marvel Super Heroes)
Complete the second tier of the challenge “Level Up"
Complete the third tier of the challenge “It's Not Over"
Complete the second tier of the challenge “Heroic Banter"
Complete the third tier of the challenge “Your Turn" (Marvel vs. Capcom)
Win a match with every normally selectable character (Marvel Super Heroes)
Complete the second tier of the challenge “Not a Scratch"
Complete the third tier of the challenge “Going Streaking"
Complete the second tier of the challenge “Chain Reaction"
Complete the second tier of the challenge “Fast Fingers"