Firstly, Tahae T; I believe you messaged me on LIVE? I'm sorry I didn't get back to you, I tend to forget about LIVE messages when I'm in-game.
Secondly, I've been playing some more today, and I'm finding myself getting really frustrated with it. The game is starting to not listen to what I'm playing. I had to try about 6 times to get it to register the E string on the 15th fret, because it just wouldn't accept that I'd played it.
The difficulty thing is really doing my head in, because it's throwing chords at me that I've never even seen, never mind played! There isn't enough "teaching" in the game, it just expects you to know everything. Doing well on one string for 2 minutes doesn't mean you're ready for major chord changes. They need to change it so that you can choose when to ramp up the difficulty, like Rock Band allows you shift up a speed in Practice Mode.
Many thanks to Cpt Slaugh7er (xboxachievements.com) for the signature!
R.I.P. to the most wonderful person to have ever lived; my Nanna. 03/11/1932 - 06/10/2013. You will be forever remembered, and forever missed. I love you so much.