Here is the full list of all 33 Mission: It's Complicated achievements.
Achieve 100% in the Gallery.
Forget to get the Possibility Stone
Complete the game with Wifi and Riptide
Get the Ultimate Ending.
Earned all 10 kisses and platonic friendships between all heroes.
Complete the game with Zael and Zirconia.
Complete the game with Nightgaunt and Zirconia.
Complete the game with Zael and Riptide.
Complete the game with Zael and Wifi.
Complete the game with Zirconia and Riptide
Complete the game with Wifi and Zirconia
Complete the game with Nightgaunt and Wifi.
Complete 10 missions in a row without injury.
Complete the game with Nightgaunt and Riptide
Get more than 10 A+'s without using "Skip."
Get an ending between two heroes.
Complete the game with Nightgaunt and Zael.
Achieve 1 platonic friendship between two heroes.
Achieve 1 kiss between two heroes.
Get more than 3 A+'s during a single playthrough without using "Skip."
Get one A+ after completing any mission.
Get the Possibility Stone.
Complete 1 park date between two heroes.
Complete second tutorial mission.
Complete 1 coffee date between two heroes.
Complete Nightgaunt's interview.
Complete all 5 interviews.
Complete Riptide's interview.
Complete 3 missions in a row without injury.
Complete Wifi's interview.
Complete Zirconia's interview.
Complete Zael's interview.
Complete first tutorial mission.