Here is the full list of all 44 Brave's Rage achievements.
Complete the game for the first time
Defeated for the first time
Complete the game with a deck that has no more than 8 cards
Complete the game with a deck that has more than 30 cards
Complete the game without equipping any gear
Complete the game with only one brave in your team
Complete the game on Challenge Tier 4
Complete the game on Challenge Tier 10
Complete the game on Challenge Tier 15
Acquire Sword of the Damned
Acquire Tower Shield
Acquire Proliferative Gland
Acquire Mysterious Berry
Acquire Excalibur
Defeat King Slime
Defeat the Impersonators
Defeat Arcane Baron
Defeat the Grave Digger
Defeat the Tormentor
Defeat Arcane Cannon
Defeat Queen Boomy
Defeat Megan, the Rotten One
Defeat Servant of the Ancient One
Defeat Pirate Queen
Defeat Suva'cillathon, The Ancient Dragon
Defeat the Corrupted Archdemon
Possess 400 coins
Possess 30 units of food
Perform 100 Insta-Blocks
Reach max class level for Don Qui
Reach max class level for Tracy
Reach max class level for Merlin
Reach max class level for Evra
Reach max class level for Sancho
Reach max class level for Brocky
Reach max class level for the Reaper
Reach max class level for Anthony
Reach max class level for all characters
Complete the tutorial for the first time
Complete to adventure under 1.5 hours in Timed Mode
Complete to adventure under 1 hour in Timed Mode
Complete to adventure under half an hour in Timed Mode
Defeat the Ancient One
Complete the game on Challenge Tier 20