Despite the unsupported label from Valve, only the videos don’t play with everything else working fine.
My experience with Warhammer 40,000 is limited to the Dawn of War games, but Warhammer 40,000: Boltgun being a boomer shooter means I was immediately interested. Having played it, Warhammer 40,000: Boltgun feels like a blend of boomer shooters with what modern Doom games are going for. Simply put, Warhammer 40,000: Boltgun is an essential even if you don’t care or aren’t familiar with Warhammer 40,000. The gameplay and aesthetic is that good. While the level design could’ve been better in parts, I’ve been having a ton of fun with Warhammer 40,000: Boltgun on Steam Deck outside of videos not playing. That’s the only caveat to keep in mind. Despite the unsupported label from Valve, only the videos don’t play with everything else working fine.