Here is the full list of all 24 Venture Seas achievements.
Experience 10 Dungeon Events
Pop Into Existance
Complete Chapter 1
Complete Chapter 2
Complete Chapter 3
Complete Chapter 4
Complete Chapter 5
Experience 50 Dungeon Events
Experience 200 Dungeon Events
Win 5 Combat Events
Win 25 Combat Events
Win 100 Combat Events
Novehk Forest - Any Zone - Max Threat Level
Ruined Alcazar - Any Zone - Max Threat Level
Sakura Jungle - Any Zone - Max Threat Level
Deepmount Caverns - Any Zone - Max Threat Level
Novehk Forest - All Zones - Max Threat Level
Ruined Alcazar - All Zones - Max Threat Level
Sakura Jungle - All Zones - Max Threat Level
Deepmount Caverns - All Zones - Max Threat Level
Novehk Forest - Defeat the Woad Daevan
Ruined Alcazar - Defeat the Rhinotaur Outcast
Sakura Jungle - Defeat Lai Li
Discover a Legendary quality item