The background shouldn't be a problem. One colleague of mine has a petit hand and didn't work reliably. Will be interested to know if it works on a mobile device.
Psychologist Barry Schwartz takes aim at a central tenet of western societies: freedom of choice. In Schwartz's estimation, choice has made us not freer but more paralyzed, not happier but more dissatisfied.
We've been using Socket.IO for years. It works well. Here is a Space Invaders demo we put together a couple of years ago. http://www.webdigi.co.uk/fun/space
Socket.IO let's you control space invaders on your desktop realtime mobile browser with websockets, long polling, etc.