Press F3 to choose language, then use 5 to insert coins, 1 to start 1 player game. Use cursor keys to move along existing lines, use Ctrl+cursor keys to draw fast, use Alt+cursor keys to draw slowly.
Good catch! Thank you for posting this. It's really crazy to be playing games I played when I was a kid (Not this game but other MS-DOS or Arcade games) in the freaking browser...
https://archive.org/details/arcade_qix
Press F3 to choose language, then use 5 to insert coins, 1 to start 1 player game. Use cursor keys to move along existing lines, use Ctrl+cursor keys to draw fast, use Alt+cursor keys to draw slowly.