Flashes

 were a limited-time currency released on August 16, 2016 as part of the SciFi 2016 Event. They were used to clear all robot on the screen during the SciFighter minigame.

They could be obtained by
 * Collecting from the Control Building every 24 hours.
 * Purchasing them in packages from the store.

Packages
A pack containing 5 units could have been purchased from the store.

US$