Here is the full list of all 21 ComixPlay 1: The Endless Incident achievements.
Finish Level 6 with more than 10 turns left (normal or hard difficulty)
Defeat the Endless before he spawns the last wave of enemies (any difficulty)
Use 20 special abilities in level 8 (normal or hard difficulty)
Cause 3000 damage with Forcer during one playthrough (any difficulty)
Finish Level 5 with full HP and revives (normal or hard difficulty)
Finish the game (normal or hard difficulty)
Finish the game (hard difficulty)
Finish the game with less than 20 deaths in total (any difficulty)
Finish the game with less than 20 deaths in total (hard difficulty)
Finish the game (any difficulty)
Don't swap out Aengus on level 8 (normal or hard difficulty)
Cause 3000 damage with Tom during one playthrough (any difficulty)
Don't let any hero die in level 6 (hard difficulty)
Kill 4 enemies with one shoot of Nebula (any difficulty)
Finish level 5 (hard difficulty)
Finish level 5 (any difficulty)
Kill 3 enemies with one shoot of Nebula (any difficulty)
Don't let any hero die on level 4 (normal or hard difficulty)
Cause 1000 damage with Forcer during one playthrough (any difficulty)
Cause 1000 damage with Tom during one playthrough (any difficulty)
Finish level 2 (any difficulty)