| Alien | How to unlock
|
|---|
| - Complete Level 2: Mess Hall Mashup.
|
| - Complete Level 3: Welcome to Erf.
|
| - Complete Level 2: Mess Hall Mashup.
|
| - Complete Level 5: Core of the Problem.
|
| - Complete Level 4: Underground and Beyond.
|
| - Complete Level 1: Stow Away.
|
| - Complete Level 4: Underground and Beyond.
|
