Added Exogene game

I uploaded the first release of Exogene, my new tower defence game. 

This game has been close to ready for a few weeks but I have been tweaking the site before releasing it. I plan on adding a few more levels and also adding a completely different mode to the game. I was to introduce a "survivor" type mode where you start with a lot of towers and then you gradually have to remove them one by one and try to last as long as you can.

The game still needs some tweaking in terms of the relative strengths of the turrets and some of the levels (particularly "back scatter") are not really tuned right yet. 

I'm pretty happy with the new "record video" mode of the serge engine. This works very well and makes the process of recording gameplay much simpler. I still need to properly edit the YouTube video a bit but just being able to start the game and have it automatically recorded is a big step forward.