Grab your pals and prepare to blast off to the Moon, for Spelunky 2 added online multiplayer today. Four players can plunder the Moon's treasures in online co-op, though the murdersome Arena mode isn't activated yet. Technically online is in "public beta" right now, so don't expect perfection, but you can play it! Eventually, you'll be able to play with folks on PlayStation 4 too.
While online multiplayer was in Spelunky 2's PS4 version when it launched, that was wonky enough that the devs decided to hold off on it when the game came to PC a few weeks later. The feature quietly launched on Steam yesterday with a wee bug that broke invitations, but shh it's fine, it's fixed now - enough for the devs to officially announce online multiplayer is go.
"What's next? Work will continue for the rest of the year and into next year to fix bugs with online multiplayer, as well as solve some of the unique design problems that have come up (hence, why we're calling this a 'public beta' even though it's possible to play through the entire game online)."
One big feature due in the first half of 2021 is cross-platform play with the PlayStation 4 version. Then once cross-play is in and "all the basic features of online multiplayer are extremely solid", they plan to add online Arena. Other plans include adding more servers around the four corners of our flat Earth, to slam in some quality-of-life-improvements, and new ways to invite folks (e.g. "Twitch, Reddit, Twitter, etc.").
Multiplayer Spelunky, historically, can be a strange and wonderful thing. If you're still plumbing the depths of its mysteries, having pals around can be quite helpful and comforting. If you've mastered it to the extent that you can run a wee model of every level inside your head, hey, enjoy adapting to the chaos of other people following their own understanding of the game and doing whatever the hell they want. Either way, it's a laugh.
If you want to shake it up solo, why not look to a Twitter bot giving out Spelunky dares that'll challenge and confound? Or for the opposite effect, playing the same seeded run over and over makes Spelunky into quite a different game.