In the mind-blown category, I've been playing the demo for a puzzle game called SpaceChem and it's pretty good. The demo takes you through all the tutorial stuff, but it takes awhile to click. On Steam: SpaceChem
It's from a basically 1-man indie studio called Zachtronic Industries. This is his first "commercial" game, but interesting side not, he made a game called Infiniminer which was the main inspiration for Minecraft.
But SpaceChem is no Minecraft, it is some crazy puzzle shit, so check out the demo!
Rock, Paper, Shotgun review.