Its a fun game about minning, sort of.
You are essentially indiana jones.
You enter randomly generated mines and try to survive and pick up as much loot.
The game is full of surprises and all sorts of tricks to learn and in general many of the game's features are not explained and you sort of have to figure them out and how to pass them on your own.
Very fun game.

LINK:
http://www.spelunkyworld.com/