Okay, this is not new, but I haven't seen it mentioned here anywhere. This is a game by Derek Yu, probably better known as the creator of Aquaria. It presents a unique, procedurally-generated adventure-platformer, with 15 or so levels...and perma-death. In each level you must brave monsters with your trusty whip, rescue damsels and collect treasures. Have fun (be sure to have time set aside for it, or you might open the game, then close it again a while later, and wonder why suddenly your calender is a week behind).
EDIT: Forgot to mention: lots of Indiana Jones references and [spoiler:2rxkh9bg]you can kill shopkeepers (at your own risk).[/spoiler:2rxkh9bg]
Sorry, if it wasn't clear from the fact that I described the game as a rogue-like, but this game is PUNISHING. You will die many, many times.
I have died 300+ times and I still haven't passed area 13 or so.
By the way, did I mention this game has lots of interesting touches? Like how the damsel you rescue also [spoiler:2iwp9r30]doubles as a nice, but unenduring throwing weapon[/spoiler:2iwp9r30]. Also, [spoiler:2iwp9r30]killing shopkeepers sets every other shopkeeper in the game against you. They are ALL armed with instant-kill shotguns.[/spoiler:2iwp9r30].
Still haven't played Spelunky but I did own the game Spelunker.
[youtube=http://www.youtube.com/watch?v=qluQqCthL44&feature=related:2tb3ud6t][/youtube:2tb3ud6t]