"It doesn't take a rocket scientist to figure out why it took iSteam barely a week ... to briefly become #1 entertainment application in the App Store." I'm no

"It doesn't take a rocket scientist to figure out why it took iSteam barely a week ... to briefly become #1 entertainment application in the App Store." I'm not so sure it's so obvious. Why is playing with steam so popular? I downloaded it and liked it, but I still don't know what was so compelling about it.