(Image credit: Unknown Worlds) After a long and legally tumultuous development, Subnautica 2 made its splashdown into early access yesterday with an impressive launch, drawing hundreds of thousands of players in its first 30 minutes and selling more than 2 million copies before 12 hours were up. Today, Unknown Worlds is following up that triumphant launch day with its first early access roadmap, giving us a glimpse at its plans for Subnautica 2's first few updates—albeit a fairly vague one. "Updates will vary from focused improvements that address systems and smaller features, to hot fixes when needed, and then our larger expansions," Unknown Worlds says in its roadmap announcement.…