Here is the full list of all 36 Gloom achievements.
The book in all its glory
A grander existence
An embryo of the cosmic way
You've got the hang of it
To retrieve what was once lost
Most renowned of them all
A place for gloom
Leo's blades and both eyes simultaneously
Well that's just sadistic
A pillar of demented art
A ghastly tide of salvation
An instrument of ascension
One-of-a-kind weapon
A place for expression and madness
An agent of secrecy
No more dreaming, no more nightmares
A pillar of demented faith
Win in less than 12 minutes
A place for ascension
A mirror of null existence
A place for silence and emptiness
A narrator of nightmares
A place for the shunned and forgotten
An orphan of spite
He had it coming
An embodiment of deific anger
A fallen deity of envy
All for one
Resilience is a virtue
A place for the lost and demented
A false prophet of ill omens
You perished in a dream
Must be routine at this point
Win in less than 8 minutes and 30 seconds
Three wins in a row
Ten wins in a row