Grindstone
49 Achievements
1000 XP
Epic
Backdraft
Complete a level with the Detonator Suit, Fireball Sword, Fire Arrow, and Firewalker Potion
20 XP
0.8%
How to unlock the Backdraft achievement in Grindstone - Definitive Guide
The last item unlock required for this is the firewalker potion, which unlocked for me on level 102.