DOOM, played over curl.
curl -sL http://doom.iteyo.eu | bash
That's it. Pipe straight to bash, get a working keyboard, and shoot some imps.
Or, if you want to do it the hard way (no shell wrapper, just a single streaming HTTP request):
stty -echo -icanon min 1 time 0 && curl -sN -X POST -T - localhost:3000/play
Source: github/xsawyerx/curl-doom · this server: http://doom.iteyo.eu