Here is the full list of all 10 Grotesque Tactics: Evil Heroes achievements.
Kill the first mushroom
Add Holy Avatar to your party
Save Mandy's chocochick
Survive the special tutorial in Station Wish
Be polite to Synthia
Find enough maidens for Holy Avatar
Convince Rukel to give back his loot
Defeat the REAL boss
Find a bonus mushroom
Find all bonus mushrooms