"Other than strumming, the touch screen is used exclusively throughout the rest of the game. The battle gems are activated by touching them with the pick-shaped stylus and some of the battle power-ups are kind of cool. They have a power-up that has fans throwing items at you in the middle of a song and you have to sign the objects before you can continue playing and I appreciated it. But then they have power-up that does absolutely nothing. It is called "Amp Overload" and it is when the speakers just blow out, but all that means is you stop hearing the song, but the game continues. How is that supposed to give an advantage to anyone? You can keep playing after the amp goes out and the notes still come at the same pace, so as long as your eye and hand coordination are solid, you can keep on rocking. I just feel they could have done more, that's all.
What it all boils down to is that it feels like Activision is literally trying to sell you the same game twice. Just like they did with Encore, Guitar Hero On Tour: Decades just feels like a half step instead of big stride forward. I would recommend a purchase if you were only getting one, but not both. Look at the song lists and see which appeals to you more and go from there. I say rent or borrow it first and then buy it if you have to have more songs to play on the go."