Game on 5 platforms matches sales of game on 1 platform. Not sure if that's a success. Great sales anyway.
Witcher 3 sold 4 million in two weeks, 1.5 million at launch
http://www.gamenguide.com/articles/24836/20150526/the-witcher-3-sales-reach-1-5-million-copies-already-nearing-the-witcher-2-lifetime-units-sold.htm