Here is the full list of all 39 Hargrave achievements.
Collect all power cells
Complete the game
Defeated Disafter
Defeat Eridanus
Die a lot
Defeat Scorpius
Defeat Perseus
Defeat Cygnus
Upgrade a weapon power to level three
Defeat Auriga
Defeat Zosma
Upgrade a weapon to level two
There is nothing to see here
Defeat Elnath
Defeat a red block
Die one hundred times
Defeat Cepheus
Just jump over it, man.
You should avoid this
Get mashed
Experience death
Pick up your first power cell
Complete the game in under an hour
Complete the game in under thirty minutes
Complete the game in under twenty minutes
Navigate through Grave Sector 1
Defeat Grave Cepheus
Navigate through Grave Sector 2
Defeat Grave Auriga
Navigate through Grave Sector 3
Defeat Grave Elnath
Navigate through Grave Sector 4
Defeat Grave Zosma
Navigate through Grave Sector 5
Defeat Grave Cygnus
Navigate through Grave Sector 6
Defeat Grave Perseus