Deadlock made the breakable pots into pumpkins and put masks on the characters

The Finals changed some in-game props into jack o lanterns you can throw at opponents to deal damage, and the maps have a spooky variant with spiderwebs and whatnot.

Phasmophobia is running a Halloween event amidst its console release, but it's mostly just playing the map to make a counter go up, kind of disappointed.

Deep Rock Galactic has the usual lobby reskin, and extra cosmetics, always fun to go back to !

Cult of the Lamb has a blood moon ritual that makes everything gloomy and summons the ghosts of your dead followers.

You can harvest them for unique decorations.

Splatoon 3 had the Splatoween Fest over the weekend. Same as last year's event, just a typical Splatfest but with some spooky aesthetics added.

Dead by Daylight added mystical smoke grenades survivors can use that are a lot of fun - many are suggesting it might become an ability as part of the main game.

No Man’s Sky has their Cursed Expedition happening now.

Pokemon S/V has a ghost type outbreak, along with Gengar raids.

I think Diablo IV is doing something too, but I have been playing NMS, Pokemon, and planning for IRL Halloween.

A lot of games in roblox ;-)

I'd say Halo should have a Haloween event.