Long, long ago, back in the prehistoric era of the mid-2000s, cellphones were, to be completely honest, a bit crap (unless you could afford a flagship model). Regardless, some brave (if not always all that talented) souls pushed onward, releasing Java-based games for these devices. They were often pretty simple and terrible to control, but they helped set up an industry that was absolutely set on fire by the introduction of the powerful smartphones we use today.
Thank you, Scott McNealy.