Take World of Warcraft, add silly humor, make it easier to play and free, and you get Dungeon Runners....which owns WoW.
Graphics: Not as pretty as World of Warcraft, but it still looks good. They get a 10.
Gameplay: Take WoW and Diablo and you get the gameplay. The gameplay gets a 10.
Sound: Nothing beats the sound of talking rats.... 10.
Difficulty: It varies, and everything is soloable, which gets it a 10.
Rip-off'ness: It's a huge rip-off, but it's a good one that you can overlook the ripping-off, so it gets a 10 (Higher numbers are better than lower numbers.)
Overall, it gets a perfect score, a 10...out of 10.