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