Disney's "Sing it: Pop Hits" features a virtual voice coach to teach players crooning techniques for sliding between musical keys, performing harmonies, and breathing properly.

Ideally, after a day's work, testers would run through the entire application, clicking virtual buttons and making sure that the right Windows or ICONS still pop up.

Instead, it is filled with pairs of "virtual" particles and their antiparticles, which pop into existence for a fraction of a second before recombining with one another and disappearing again.