Here is the full list of all 33 The adventure of Kroos achievements.
Pass all chapters of Snow Forest
Pass all chapters of Starlake Jungle
Pass all chapters of Eternal Victory Castle
Pass all chapters of Crystal Source Land
Pass all chapters of the Dark Dungeon
Pass all chapters of the Prison Tower
Collect 8 weapons
Collect 16 weapons
Collect all of the treasure boxes
Aquire 10,000 pieces of Dark Crystal Fragments in total
Aquire 100,000 pieces of Dark Crystal Fragments in total
Aquire 1,000,000 pieces of Dark Crystal Fragments in total
Dicover 5 hidden regions in total
Discover 20 hideen regions in total
Defeat Uderik without hurt under the normal mode
Defeat Regina without hurt under the normal mode
Defeat Ferell without hurt under the normal mode
Defeat the Comander of the Castle without hurt under the normal mode
Defeat the Butcher without hurt under the normal mode
Defeat the Fire Golem of the Castle without hurt under the normal mode
Kill the white tiger Dumb at the first encounter
Kill Kuta and Dumb without hurt under the normal mode
Fall to death
???
Be killed by a bomb stone
Raise the health skills to the full level
Raise the defense skills to the full level
Raise the attack skills to the full level
Raise the health skills and the defense skills and the attack skills to the full level