Maybe you saw it, maybe you didn't, but this last week-end the Humble Bundle Mojam took place. (I'm sorry, I would have said something before the week-end, but I only found out myself on Sunday. Yeah, I'm tuned in to all the cool happenings on the interweb, I am...) In short: you could watch Mojang create a brand new game in only sixty hours. Something like a Ludum Dare, but then done by a whole team and with the proceeds going to charity. Apparantly you could even vote on the theme which, naturally, turned out as a steam-punk Egyptian themed multiplayer shooter.
I didn't get to watch much of the creation itself, but you can check out a previous post of mine on Notch taping his Ludum Dares to get an idea of the process. The difference that a bigger team brings ? Better art and multiplayer goodness, I would say.
Best of all, if you donated something, you not only get to download and play the game, you also got a copy of the final source code! Now that's a big bonus to a software geek like myself. I have only looked at it briefly, but the structure seems very similar to what I have seen Notch code in his Ludum Dares. In particular they are still juggling all the pixels themselves; no real hardware acceleration is used. It's basically writing to a back buffer and then blitting it to screen. Easy. (Right?) :-)