N-Gage used to be a phone... a terrible phone for gaming. The games were on small carts but to change games you had to remove the battery.

The N-Gage QD came out afterwards which corrected a lot of the original N-Gage phone problems, but it was still rather crappy.

(Why bother making a gaming phone when most of the time you couldn't play sound properly?)

All games for the N-Gage phones were simply Java applications put on carts.

The N-Gage brand became an Xbox Live style gaming platform which apparently almost no one uses. Nokia also let go their entire Canadian N-Gage division, all of whom were working on games for the platform.

As far as I know, N-Gage is dead in the water.