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