Do you like zombies? Do you like sandbox survival? Do you like collecting cars and rare guns with loads of customizable parts? Do you like blocky graphics? You'll love Unturned!
http://store.steampowered.com/app/304930/
I recently started playing this game, and it's been a blast. It's free to play on Steam at the moment, and is in early alpha as far as I understand. It's developed by some 17-year-old, which just makes it even more impressive. At first glance, it looks super rough and sorta ugly, but once you start playing, it has much of the same charm as Minecraft. I highly recommend checking out the community wiki, as the game is pretty darned difficult in the beginning if you don't know what to do.
I have personally pretty much "completed" the game, as I now have every single vehicle (and even the rarer desert camo version of the already extremely rare APC), and also every single gun and such. I've built a base, and I guess I should build a garage complex for all my cars. My biggest dream is to race with the Roadsters some day, when I can find somebody to play with me online. As far as I've heard and seen, playing with friends is the optimal way of playing, but I don't know anybody who plays it. Shit sucks.
Anyway, here's my car collection: