I can applaud Wolfire's ambition, and I appreciate that they bundle Receiver---which is a wonderful little bite-sized FPS---with Overgrowth, but that doesn't do much to offset two very key facts:
-Overgrowth is still in alpha, and a buggy alpha at that.
-It has been in alpha since 2008. SIX WHOLE YEARS.
I realize Wolfire is a very small studio, but thirty dollars for a buggy alpha is an extremely bad deal. They're at least transparent that it's an alpha, but I bought the game years ago before it was Greenlighted on Steam never even imagining that they would take this ridiculously long.
If you want to give Wolfire your money, go ahead. But keep in mind that this is nowhere NEAR a complete game---it's basically only a level editor/modkit and some assets at this point---and it's not clear when, if ever, a beta and/or a complete game will be forthcoming.
I recommend just buying Receiver instead. It's finished, it's cheap, it's interesting, and overall not only is it more bang for your buck but it still supports Wolfire.
If Wolfire learns some better time management skills and gets things moving, I may rewrite this review after sampling new features and content. Until then, this is a bad deal, and an example of the shortcomings of both Steam Greenlight and, to a greater extent, the whole concept of 'early access' in game sales.