So Terraria. First time i ever played this, I spent about the next 25 hours playing it. The day after, I woke up, and instantly went back to it.
The game is inspired from Minecraft, and might remind some people of it. But the game really got far more to offer than Minecraft in my opinion.
Random Goblin invasions, large bosses, and hordes of Zombies, Skeletons, Floating eyeballs, and a whole ton more of enemies attacking you underground, at nighttime, or while you're fighting your way through the corrupted wilderness. At least 10 different materials gives you a wide range of things you can craft, or combine. There is over 7 NPC's you can make a house for to make them stay. Really good music . A wide range of weapons, armor, and so forth.
And with the latest update (1.1.0) the game offers even more stuff, such as cables, traps, mechanics, The Hallow, and last but not least over 3 new bosses.

It's a game i highly recommend trying.
Sadly, this game is Windows only. Sorry, Mac users.

4/5

This game is the most interesting single-player fantasy platforming game i've played.
It's like a fairy tale, except that you're a part of it the whole time.
If you really like good platforming games that's a little over the unusual, you should at least take a look at it.

Aeiou.