Spelunky is a NES-style game that allows you to explore caves, get treasure, buy items, etc. It's a basic platformer, where you play as an Indiana Jones-type character, and is located at http://spelunkyworld.com/ I know it's free, and I believe that it's open source.
if its open source or not its in a zip look http://www.derekyu.com/games/spelunky_1_0b.zip
which means if its free some one could create a paf live installer
60\/\/ 2 /\/\3 4 1 4/\/\ 12007
bow to me for i am root
As long as it takes your settings with you, I'm fine with it. Annoying having to restart the my game just because I play it on different computers.
It stores your settings in the registry. It's a really fun game, though, and if you get into it you'll want the many different things unlocked. But that will all involve hacking it to not use the registry.
The "portable" solution that the Spelunky wikia offers, involves exporting and importing registry settings. I thought portableapps.com tried to stay out of the registry if at all possible? It is open source but the source is for a game creation engine called Game Maker.
Just came upon this game today, and am wondering if I add myself to this conversation, maybe someone'll pick it up... Well, one can hope. And, source for 1.1 is out. And has been for a good bit.