Need small hands to play. It's like GH3's retarded brother. The tracks aren't fresh at all.
This game is GREAT...if you're 6! Geeze man my hand hurts so much after just playing one track.
If you want specs, there are 4 buttons, each 1.2cm big and separated by .3 cm. Total fretboard is 5.7CM across. It's THAT SMALL.
While there is a hand strap, it doesn't seem to work well if you have normal sized hands. On top of that, you have to hold the DS in your hands with this button device at a weird angle. Your wrist WILL hurt. Additionally, if you put pressure in the wrong spot, the button device will pop out and you have to RESET your game.
The tracks aren't fresh, most of them are recycled from GH3. The new tracks aren't very great.
The only cool feature of this game, and I hope they put it into the future GH games is the pause feature. When you unpause, the song backs up about 2-3 seconds and leads you into the notes you haven't played yet. It's good because you can pause inbetween streaks and probably get the streak.
I say skip it. Don't waste your money.