Yes, I think gaming on a smartphone, and tablet is the most convenient and inexpensive form of gaming for most people since for 100-199.99 dollars or less you can have a device which can play games, and there are plenty of free games, and ad-supported free games for you to download and play. Plus, once you downloaded and installed the games, you don't need to subscribe to Internet service to play them like flash and free online games.
Plus, most people need a cell phone, so they won't be spending an additional few hundred dollars to buy a handheld game console for playing simple games like Angry Birds, Fruit Ninja, Temple Run, etc.
Same, for me, I used to play Tetris, but does not play any more, but it is sure more fun then Minesweeper, Solitaire, and less-active games.
I Lumines which is available for the PS2, PS3, Xbox 350, and Vita looks like a fun game based on Tetris, but I never played it since I rather play and spend my money on more action packed games. If it was free, or under 10 dollars I might play it.
I think that tablet and mobile gaming is cheap yes, but it's also a great market. Sure games can only sell for a few bucks or even a dollar. However, there are so many people that use phones now that have features that would allow for that sort of gameplay. And now you see people of all ages, genders, and social types playing these simple yet addictive games. I think it's a growing market, and as for your quest, yes it is the cheapest form of gaming. However, for full on gaming you can't beat a nice round or two of Halo on the Xbox on an iPhone
I believe the iPhone 4S is fast enough to run 3D games like Halo for the Xbox 1 since Technology as advance since the early 2000s, and SmartPhones have Bluetooth wireless connectivity or wired connectivity in some cases, so you can add a controller.
Some SmartPhones can also be connected to a monitor, or TV wirelessly or by Mini-HDMI, so you could have a console gaming experience if you try hard enough, but there are not many hardcore games for phone.
