Here is the full list of all 18 Glo achievements.
Complete first level.
Complete the game.
Find first memory.
Find all memories.
Beat first boss.
Beat second boss.
Beat third boss.
Beat fourth boss.
Escape the darkness in one sitting.
Use a sticky bullet.
Use a glo bomb.
Use a pinball bullet.
Complete a speed run.
Die 10 times in one level.
Die 100 times in one level.
Kill 4 sliders in 3 seconds.
Escape the darkness in one sitting with no deaths.
Kill 2 enemies with 1 bomb.