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