Frustrating to see so many "not recommended"s because "The developer has abandoned".
Visit the actual blockscape webpage/forums and you'll find out that he's very active. They keep a dev blog and are very active with the community there. ***There haven't been many updates because the dev has been doing a complete engine re-write, which (from the devlog sounds like it's going well)
Do some research before you jump to the conclusion that the developer isn't going to update/isn't working on the game. This game is early access and nowhere near the finished product. The graphics are absolutely stunning and if you can read that statement and cringe then you need to not pay $20 for a game you know you won't be able to run.
I bought this game in early 2013 and it has come a very very long way. At that point there was nothing but a "creative" mode essentially with a survival mode that only differed by having you obtain the materials before you used them at seemingly random harvest rates.
Now theres much more to the game, even with a well done electrical system. If you buy this and find yourself floundering with the insane amount of build control, visit the official blockscape forums and download some of the maps other players have made for inspiration. The landscapes are so stunning that I often find myself forgetting where I am (irl) and getting lost for hours just exploring the world, and never finding a place that I want to desicrate with my mediocre building skills. (I don't have much time on it on Steam because most of my playing was before this went to Steam).
TLDR: If your computer isn't great, your going to have lag (it's graphically stunning), check the minimum specs before you buy. Dev hasn't abandoned, he's rewriting the game engine shouldn't be much longer. If you hunger for updates/info/community check out the offical blockscape forum.
Here's a link to the devlog http://forum.blockscape.com/viewforum.php?f=27