The first ever game which was installed into a Cell Phone was Snake on some selected Nokia New models in 1998. Snake and its differnet versions have since become the most-played Cell phone game on the Universe, with over a billion people having played the game.
Cell Phone games are played using the technologies present on the Cell Phone itself. For Network Games, there are many other technologies in common use. For Example include text message (SMS), multimedia message (MMS) or GPRS location identification.
There are several non networked applications, that simply use the Cell Phone platform to run the game software. The games may be installed over the air, they may be side loaded onto the handset with a cable, or they may be embeded on the handheld cell phones by the OEM or by the mobile operator.
Mobile games are usually downloaded via the mobile operator's radio network, but in some cases are also loaded into the mobile handsets when purchased, or via infrared connection, Bluetooth or memory card.

bravenet.com