Here is the full list of all 26 Excubitor achievements.
Pass the tutorial level
Get 10000 voidshards
Get 250000 voidshards
Get 600000 voidshards
Get 500 kills
Get 2000 kills
Get 5000 kills
Get a blast from the past
Best confetti
Parteh time
Bro?
Light a bonfire
Completed chapter 1
Completed chapter 2
Completed chapter 3
Completed chapter 4
Pick up 1 powerup
Capture 1 voidshard container
Max out the shield system
Max out the armor system
Max out the engine system
Max out the weapon system
Fully upgrade everything
Fully upgrade a weapon
Fully upgrade a turret
Pass all levels in New Game+