The code of the game is about 60,000 lines, not including any assets.
Compare that to GTA: Chinatown Wars that currently have about 800,000 lines of hand-optimized source code
Still it's so freaking much for one single person to make a code 60000 lines(How much is it acctually? I'm not a programmer), and we shall remember that he also had done the graphics and composed the music all by himself!
Source of information: http://blog.differentpixel.com/archi...Interview.html
http://www.gamekyo.com/news29038_gra...t-screens.html