I just found this little game, http://www.spelunkyworld.com/. It's a platformer game with an Indiana Jones kind of theme to it, with levels that are randomly generated each time you play. You go through these levels collecting treasure, which can be used to buy useful objects, like bombs to clear walls, or climbing gloves, ropes, etc.
It's also rather difficult, and if you're dead you're permanently dead, so it has a bit of a roguelike vibe to it. I haven't managed to make it through all 20 levels yet.
It's pretty addictive, give it a try.
http://www.youtube.com/watch?v=5x_V9k9tonM