This game is inspired by a famous old arcade game from the late 1970's, whose name is a registered trademark that we can't use. Lukily, it looks like reusing the ideas of an old game is still permitted. For more details, http://www.copyright.gov/fls/fl108.html. This Yoctopuce work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License. You are allowed to share and adapt this game for your purposes, but in any case you must clearly attribute the original work to Yoctopuce by providing a direct link to Yoctopuce blog article that describes it.