Brawlhalla

A game currently owned by Ubisoft, it has super smash bros type gameplay and has a player base of 50 million and climbing.
In game purchases.
This game features many in game purchases, a player can earn coins to unlock characters or spend money to buy them.
Crossover Characters.
There are alternate versions of characters that come from other franchises in the game. 
Events and Competitions.
There have been many competitions for Brawlhalla, cash prizes have been handed out and competitions are usually held often.
Playability.
Brawlhalla is playable on most devices and runs well on them all.