Valve revealed that Poncle's Vampire Survivors had a strong launch on the Steam Deck for the month of October. Not only did it have the most concurrent players per day, it also took top spot for October's most-played game on the handheld overall. 

Vampire Survivors is a bullet hell roguelike that left Early Access and reached Version 1.0 on October 20. Suffice to say, its popularity on Steam and the PC version of Xbox Game Pass means it'll have legs for a good long while.

Other October releases with a high concurrent player count include Atlus' Persona 5 Royal, Naughty Dog's Uncharted: Legacy of Thieves Collection and WB Montreal's Gotham Knights. Interestingly, the latter game isn't actually verified for the Deck per Valve's guidelines like Uncharted or Vampire Survivors, but that hardly seems to matter to players. 

Persona 5 Royal may have taken second place, but its Steam Deck success validates Sega's recently stated commitment to remasters and remakes. The 2020 re-release of Persona 5 came to non-PlayStation 4 consoles towards the end of October, and it's been a hotly requested title to be played on a handheld, such as the Deck or Nintendo Switch.  

Among October's most-played Steam Deck games after Vampire Survivors were Elden Ring, Cyberpunk 2077, and Stardew Valley. 

Steam Deck's most-played games are judged by hours played, which puts some perspective Cyberpunk in particular: in September, developer CD Projekt Red boasted that the game reached 1 million daily players.