The Eternia Crystal has many different skins that players can choose. The skin can be changed in the main menu screen where the player selects a character. Each skin is purely cosmetic, and therefore does not affect the crystal's health.
The different skins are obtained by completing achievements in game and are as follows:
| Unlock-able Crystal Skins | |||||
|---|---|---|---|---|---|
| Image | Name | Achievement | Image | Name | Achievement |
 | Classic | None |  | King's Crown | O Mighty Smiter! |
 | Crystalline | Good Student |  | Geode | And This Is My Weapon |
 | Mystical | Pupil |  | Cell | Veteran |
 | Molecular | Brute Force |  | Runic | From the Depths |
 | Landscaped | To The Rooftops |  | Waterfall | Defender of Etheria |
 | Eastern | A Taste of Victory |  | Western | A Challenger Approaches |
 | Fantasy | A Matter of Perspective |  | Urn | Perfectionist |
 | Organic Goblet | Group Hug |  | Book of Souls | Obedience Training |
 | Goblet | Survivalist |  | Skulltacular | Daredevil |
 | Money | Master Banker |  | Horned | Iron Man |
 | Sky City | Mastermind |  | Bio Container | Catch 'em All |
 | Fusion Core | Dungeon Defender |  | Obelisk | Team Effort |
 | Birthday | Nightmare Anniversary Defender |  | Trick or Treat! | Pumpkin Party Nightmare |
 | Pandora's Box | Defense is the Best Offense |  | You Are Trendy | Legendary Defender |
 | Lovely | Playin' Mythical Cupid |  | Ultimate | Ultimate Defender |