(Image credit: Krafton) Subnautica 2 launched into early access today, and at least one new feature makes it an improvement over the original: multiplayer. Up to four players can play Subnautica 2 in co-op, so you can have some company as you plumb the depths of the alien ocean world. We got our hands on Subnautica 2 a bit early, so we were able to experiment a bit with multiplayer, and the new system is lacking in certain ways but pretty generous in others. Here's how Subnautica 2's multiplayer works . Tyler, however, who was joining my game, had to use a brand new character with no progress. Subnautica 2 doesn't seem to work like a game such as Valheim, where you can bring existing characters and all their stuff into someone else's world. That's a bit disappointing—it would be great if Tyler could have taken his existing singleplayer character into my world with his gear, inventory, and progress intact.…