From the review:
"I've played Activison's cash cow for dozens, if not hundreds, of hours. I might even have pictures of the blisters to prove it. I've also become very tired of the franchise and later, the genre, only to return shortly after. As of writing, I've pretty much decided I'm done with the glorified "Simon" using plastic instruments until additional innovations are brought to the table.
That pledge didn't last long, as "RockFree" has me interested once again, mostly because it's the product Activision is scared to create."