Probably the easiest way to describe Spelunky is that its (kind of) like La Mulana meets Nethack – every time you play the levels, items, monsters, and so forth, are all procedurally-generated. And the terrain is destructible and there are quite a few ways in which the various game elements can interact with one another.
Which gave me an immediate nerdgasm, because not only is Aquaria an excellent excellent game (Ecco the Dolphin meets Loom), but Nethack (along with other Roguelikes) is arguable the ultimate geek game.
So, what are you waiting for, go get it and play.
From Wired Blogs.