He started out with some basic swing component/boiler plate code.
This is the third time I have watched him make a game like this. The last time he made a dungeon crawler but did it in a really novel way.
Just like last time he had the pov moving back and forth while he tweaked the walls and floors while in debug mode. This allowed him to tweak each part and get them looking correct. He spoke a lot more about what he was doing in the beginning and spoke less as the weekend went on.
The resolution on livestream was not as good for me as it was on justintv so I could not see what he was writing to get that affect. I assume it was nothing more than sin times some fraction over the x axis.
The time before that was metagun. A fantastic 2d platform game.
The thing that impresses me is that he doesn't stop to think too much. He just goes for it. I think I need to employ more courage to writing code like that when it comes to competitions.
I always get inspired watching these. I learned a ton.