Overgrowth is one of those games that has been in development so long that it was unclear if it would ever hit version 1.0. Initially beginning development in 2008, it became a part of Steam Early Access in 2013.
Since then, the game continued to expand its fanbase, always adding new features, fixing bugs and generally keeping people intrigued by development. Now Overgrowth has finally exited Early Access all these years later.
There are a variety of story modes and campaigns, as well as tons of player-made mods to test out. Overgrowth is available with a launch week discount of $20.99 on Steam.