Circus Boom tournament for collecting boosters

The goal of this tournament is to collect as many different boosters as possible. 

To take part in the tournament, you should craft and activate at least two boosters on a level that you have won, open the tournament window, and claim your gift. The boosters you crafted are only counted if you successfully complete the level after activating them. If you fail to complete the level, the boosters you collected are lost. 

After you claim your gift, you are added to the list of tournament participants in one of the leagues. You can collect boosters by completing levels in both town buildings and temporary events.