Here is the full list of all 20 Hexodius achievements.
Perform your first dimensional travel.
Possess all the equipments and upgrades in Story mode.
Complete 42 arenas in Story mode.
Travel to the 7th dimension.
Obtain an A rank or better in all the Arcade rooms.
Earn 500 credits in a bonus room.
Discover all the bonus actions.
Finish the Boss Rush mode.
Do a chain of 50 or more.
You have encountered all the basic enemy types of the game.
Complete a world by finishing all the arenas in the Story mode.
Achieve the story mode in Hardcore difficulty.
Possess 2000 credits in Story mode.
Do at least 10 multikill bonus actions during an arena.
Do 8 different bonus actions in an arena.
In Story mode, finish an arena with fully equipped B.O.B.
Travel to the 6th dimension.
Obtain an S rank in any arena.
Acquire 10 equipments and 10 upgrades in Story mode.
Achieve the Story mode in any difficulty setting.