The smash indie hit Vampire Survivors is planning to finally move over to their newer and upgraded game engine on August 17th.
A big change for the game to go from Phaser to Unity but it should hopefully be well worth it. This will bring with it better cross-platform support, big performance improvements and give the developers a better platform to continue expanding the game as time goes on - like for the upcoming local co-op mode.
The news was announced on Steam where they've also noted that Steam Trading Cards are now live, plus IGN recently got a co-op hands on with an unfinished build that might answer some questions for you. The developers say they're still working on it, trying to put in as many co-op options as possible along with a special item only in co-op.
On top of that they're also hosting a real-world co-op event hands-on in early August in London (UK). More details on that when they announce it.
The original co-op trailer if you missed it:
Available to buy on Steam. It is Steam Deck Verified and works great on desktop Linux with Proton too. It does have a Native Linux version in Beta but it's not really clear what they plan to do with it there.