Maia, the Dungeon-Keeper-in-space game from Simon Roth that's been forging through Early Access for the best part of a year, is utterly fascinating. It's dedicated to accurate simulation to the point of internal bodily functions governing whether a colonist lives or dies, and it's full of future tech based upon real world science extrapolated to logical outcomes.
Each new update brings more systems, and another level of complexity to tinker with. 0.45 adds a bunch of research options which provide perks to help survival - which is a lot more practical than the last update, which brought procedural haikus to the mailing system colonists used to communicate. Simon's put together a video showing off the new features.
Of the full list of changes, the new AI to allow colonists to interact with one-another on tasks is the most important. At EGX, Simon said this stopped colonists from moving around the base in trains, all targeting the same task before being unable to take part when the first member got there and splitting off. It should also speed up the sometimes slow early game that I've experienced in various demo builds.
There isn't currently a plan for release, or moving to the beta stage, but updates are fairly regular with 0.44 coming out a month ago and 0.43 in mid June.