The $70 price of the iCade Mobile is way too high: after all, you can buy a Nintendo DSi for $100. It's too high to be a mere novelty, too. The iCade arcade cabinet gets away with it because it looks far cooler, is made of better materials (an arcade-quality joystick), and suits what it's made for: old arcade games. Old arcade games don't even play all that wonderfully on the iCade Mobile, because the loose-feeling D-pad, while responsive, just doesn't feel as great for games like Defender or Joust.
Pairing via Bluetooth is a pain at first: you have to press all four shoulder buttons and then enter a numerical code via the D-pad and buttons, each of which has a number embossed on it. Once it's paired, all you have to do is turn it on next time. The iCade Mobile uses two AA batteries (included), but you have to unscrew the back of the unit first.
The rubber housing for your iPhone or iPod Touch (an included extra rubber backing fills spare space for the thinner Touch) feels cheap and stretches awkwardly and unevenly around the phone. It's sturdy once inserted, but you can't access side volume or standby/sleep buttons. A swivel lets you orient the iPhone in landscape or portrait mode.
Word of warning: although the iCade has more than 100 games that support it, not all of those work for the iCade Mobile. I realized that when I found I couldn't play Super Crate Box. I'm sure more games will include updates for iCade Mobile compatibility, but right now it's frustrating.
As a novelty item for the mobile gamer who has everything, the iCade Mobile could be a clever but expensive gift. It isn't anything more than a novelty, and it certainly doesn't turn an iPhone into a PlayStation Vita alternative. If you really care that much about buttons, go buy a Vita or PlayStation 3DS instead.