Why doesn't Tetris work?

Question

GitHub

Found a cool toy: Tetris open source,
www.xarg.org/project/tetris
went to github downloaded the archive, there are two files
tetris.html
tetris.js
This is what I get:
https://www.dropbox.com/ s/n6svvfzwmyhyu94/Screensh...
How to be? Please take a look, I may be doing something wrong.
Uploaded to hosting, the same thing, where is the error?

Answer 1

Take a look at the browser console.