| Unlockable: | How to Unlock: |
| Play as Boogey | In Mission Mode Finish Mission 9 in "Tier 4" |
| Play as Chicken | Beat Story mode as all characters and accumulate 10 hours of gameplay. |
| Play as Dracula | In Mission Mode finish Mission 5 in "Tier 3" |
| Play as Eris | Beat Story mode as Billy, Mandy, Grim, or Irwin. |
| Play as Fred Fredburger | Beat Story mode as Billy, Mandy, Grim, or Irwin |
| Play as General Skarr | In Mission Mode finish Mission 6 in "Tier 4" |
| Play as Hoss Delgado | Beat Mission 9 in Tier 1 in Mission mode. |
| Play as Jack O'Lantern | In Mission Mode finish Mission 9 in "Tier 2" |
| Play as Lord Pain | Beat Mission 9 in Tier 5 |
| Play as Mogar | Beat Story mode as Billy, Mandy, Grim, or Irwin. |
| Play as Nergal | Beat Story mode as Billy, Mandy, Grim, or Irwin. |
| Play as Nerglings | Beat Story mode as all characters. |
| Play as Vikings | Beat Story mode as all characters and destroy every letter in the credits sequence. |
