Name brand games appealled to my kids because they love Scooby Doo and Bratz.
Price appealled to my family because it was considerably cheaper than Wii, Playstation, etc. that were out at the time. The system and the games were much more affordable.
Some of the games were extremely easy and some where a tad bit difficult for my 7 and 6 year old. By the way I went by my kid's ages (6 & 7 at the time).