Actually, I believe I saw several times more marketing material for the original N-Gage than every other Nokia product combined. There were ads in magazines, floor-standing displays in stores, and more--everything Nokia doesn't do in the United States for other products.

Nokia actually tried to market N-Gage. One of its major problems then was product design. The much lampooned "sidetalking" killed the devices as phones, and the placement of the game cartridge slot behind the battery (plus a weak game lineup) killed the devices as portable game systems.

Additionally, during the time of the N-Gage devices, gaming wasn't as socially acceptable for adults as it is now. At the same time, people weren't yet commonly purchasing mobile phones for children. So, there wasn't much of a market.

Now, gaming on mobile devices is considerably more socially acceptable (at least for casual games) and support for it on devices has become a given. I can't see a clear need for a gaming brand on a given set of phones, unless you're bringing an established name over from the gaming world: Xbox or PSP Phone, for instance.

Nokia needs to provide a good gaming experience on their devices, particularly the highish end ones. They also need to gather a good line up of titles. What they don't need is N-Gage.