Happy birthday, Overwatch.

Blizzard’s special event for the team-based shooter’s first anniversary is now live. It will go on until June 12. Since launching on May 24, 2016, Overwatch has attracted over 30 million players. It’s also a paid game, not free-to-play. The base version for PC costs $40, while Overwatch costs $60 on PlayStation 4 and Xbox One. So all 30 million of those players had to pay money up front to get into the game.

This is the sixth event Blizzard has run for Overwatch. These give people an excuse to regularly come back to the game to see the new cosmetics and play modes. And since those costumes and other goodies are available for a limited time, it encourages players to spend money on loot boxes for a chance to unlock them.

This anniversary event adds over 100 new cosmetic items, including legendary skins for many of the heroes (those are the rarest costumes, as they alter a character’s appearance). It also introduces three new Arena maps: Castillo, Necropolis, and Black Forest. These join Ecopoint: Antartica, which was the only map for 1-vs.-1 and 3-vs.-3 matches.

The event also adds new three-vs.-three and one-vs.one modes. Lockout Eliminations has two teams of three players fighting in multiple rounds. If a players wins a round as a hero, that character becomes unavailable for the rest of the match. Limited Duel has two players going head-to-head, but both of them can only select heroes from the same limited pool.

Blizzard has also released some bug fixes and balance changes for Overwatch. You can read the full patch notes here.