well its a totally different game that you cant really compare to any other really... i mean , DDR has the dance pad that takes a long time getting used to. i know GH and DDR might seem the same in terms of arrows/buttons going up or down the screen, but its highly addictive and its gotten to the point where my girl friend (who only like viva pinata for 360) is dominating my gaming time. i used to be into DDR but found myself not really improving that much so i got over it.. i think thats the main difference between the two. But i think you should probably go to best buy or a friends house that ownes it to test it out and see for yourself

GH2 was my first GH game and i loved it, and i had it for ps2 at that time. no achievements and no leaderboards and it was still fun then.