Here is the full list of all 21 Braveland achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Sigurd defeated.
Game completed without using the easy level of difficulty.
Game completed using only the hard level of difficulty.
Rain of Fire spell learned.
100 units encouraged.
All four equipment items on.
Defense spell used 10 times.
Arakin defeated.
Acceleration spell used 10 times.
1000 damage inflicted to the enemies with Fire Arrow.
Page on Facebook or Twitter visited.
Fromm defeated.
Two warrior abilities learned.
Equipment item on.
Treasure chest collected.
Warrior ability learned.
You defeated the army without losing a single warrior.
Peasants have joined you.
Three treasure chests collected.
The best equipment of all four types on.
All warrior abilities learned.