FATHOM took about 10 days to make. I used Eclipse + Flex Builder 2.0 plugin for the Actionscript coding, Photoshop CS4 and Cosmigo Pro Motion 6 for the graphics, and SFXR for the sound effects. I collaborated again with the inimitable and utterly badass Danny B
for music, who put together some really memorable stuff. The game is only about 200KB without the music, which composes the other 12 MB or so of content! But I think it's worth it.
Also, the Flash framework that powers this thing should finally get a public, open source release in a few weeks! Thanks to everybody that helped out by playtesting and tolerating me during the development of it, including Alec Holowka, Ivan Safrin, Kyle Pulver, Myron McMillin, Ed McMillen, Danny Baranowsky, and my wife Bekah!
EDIT 1 - ALSO THANKS TO BRANDON FOR PLAYTESTING TOO
EDIT 2 - Tommy Refenes and the formidable Guert also playtested, so thanks to those guys too!! I ALWAYS FORGET PEOPLE WHEN I DO THESE THINGS