Part 2, tunnel generation: http://ehouais.net/2013/04/js1k-2013-part-2-tunnel-generatio...

Part 3, rendering: http://ehouais.net/2013/04/js1k-2013-part-3-rendering/

Entry demo: http://js1k.com/2013-spring/demo/1555

Source: https://github.com/ehouais/js1k