A game like Legend of Grimrock 2 could absolutely run a successful early-access campaign. Its predecessor was a solid first-person dungeon-crawler and developer Almost Human has rightfully earned goodwill. I'm sure plenty of fans would happily pay for the chance to play an early build of the sequel. But in an all-too refreshing move, that's not happening.
Speaking to Rock, Paper, Shotgun, the studio says "We are kind of old-fashioned and want to release the game in a polished condition, so Steam Early Access is not planned. We are going to have preorders though." Which is respectable. As much as I feel like paid alphas have their place, some more than others, I'm ideally always looking to play a game when it is at its best -- and that sentiment isn't exactly compatible with the early-access model.
Development on Legend of Grimrock 2 has reached a point where the title can be played from beginning to end and all planned features are implemented, so it's coming along. Almost Human is now working on polish and balancing, among other tasks, and expects to release this year.
Legend Of Grimrock 2 Out This Year, No Early Access [Rock, Paper, Shotgun]