One of the last blog posts mentions private beta keys.
Maybe the other commentors are some of the lucky 100?
They seem to be quite active since I've seen PlanetBase mentioned a few times before.
Madruga made a statement that the game was feature complete, and aside from any bug quashing or maybe paid DLC in the future, they felt they'd delivered on what they promised. This was on their community forum, on a page now deleted: http://planetbase.madrugaworks.com/board/viewforum.php?f=3
This was referenced and discussed on the sub over a year ago: https://www.reddit.com/r/Planetbase/comments/3v1ze2/is_planetbase_still_in_development_or_is_it/
For what it's worth, I submitted this to the support forum on the Madruga Works website, and it was classified as "D" (minor but we'll fix it if it's easy), and it looks like it was easy, and a bug-fix for it will be in the 1.0.7 patch.
http://planetbase.madrugaworks.com/board/viewtopic.php?f=9&t=963
Project Title: Planetbase.
Promotion Type: Greenlight.
Promoter's name and role: madrugaworks, creator.
Greenlight: http://steamcommunity.com/sharedfiles/filedetails/?id=472081504
Video: https://youtu.be/KEW_yCDB6GM
Web: http://planetbase.madrugaworks.com
Planetbase is a strategy game where you guide a group of space settlers trying to establish an outpost in a remote planet.
In the game you play the role of the base architect and manager, telling your colonists where to build the structures they will need to survive. You will have to ensure that they have an constant supply of oxygen, food and water to stay alive.
You will get them to collect energy, extract water, mine metal, grow food, manufacture bots, and build a fully self-sufficient base. Even if the game is not intended to be a simulator, all the mechanics are plausible, and based on what the expected challenges of establishing a colony in an new planet would be.