Sellyme

A Good Start

Get through The Graveyard

Halfway There

Get through The Catacombs

Regicide!

Defeat the Ghost King

I Hate The Ghost King

Defeat the Ghost King three times

Quad Kill

Defeat four enemies at the same time

A Different Exit

Find a secret level

Bye, Moai

Destroy the Moai in the Snow Cliffs

Long Live The Queen

The Last Leg

Get to The Depths

Cool New Looks

Unlock every alternate skin

Original Set

Unlock all nine original characters

The New Kids

Unlock the three newest characters

One True King

Defeat the Ghost King as the Ghost King

Century Mark

Score 100 or more points in a game

Buried Deep

Secret Shopper

Get GhOsTY

Beat the game with GhOsTY (only active in January)

Tourist

Beat the game in Tourism Mode

It Wasn't Actually Endless

Play Endless Mode. It does end.

I've Seen Things

Get a score of 40 or more in an Endless game