Here is the full list of all 23 Project Hedra achievements.
Specialize into an assassin
Specialize into a ninja
Specialize into a druid
Specialize into a hunter
Specialize into a berkserker
Specialize into a paladin
Specialize into a scout
Specialize into a necromancer
Learn all specializations
Travel to another dimension
Spend at least 5000 gold
Obtain a bee companion
Help 10 villagers in need
Equip a hat
Fish 50 items
Craft food at a campfire
Craft a boat
Respawn 50 times
Kill 100 enemies