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