Complete the indicated task to unlock the corresponding challenge.
Arena challenge - How to unlock
Attrition - Collect the Arena Token in Level 2 - Mess Hall Mashup.
Big Hits - Collect the Arena Token in Level 4 - Undertown and Beyond.
Magnet - Collect the Arena Token in Level 1 - Stow Away.
Malfunction - Collect the Arena Token in Level 5 - Core of the Problem.
No Time for Heath - Collect the Arena Token in Level 3 - Welcome to Erf.
Sale on Turrets - Collect the Arena Token in Level 6 - No Time for Sightseeing.
