Hoping to attract more players, Bungie decided to roll out a PvE experience for Marathon this week. This is Vault Breaker, a experimental mode that can be played solo or in a duo to take on AI-controlled enemies.

While the number of concurrent players barely reached 5,200 on Steam on July 20, SteamDB reports that Marathon hit a peak of 14,809 concurrent users the following day with the release of Vault Breaker.

It remains to be seen whether this momentum will continue. For now, that doesn’t seem to be the case, as the number of concurrent players on Steam has dropped back down to 5,300.