I'd say it is okay, although annoyingly due to the trend of persistent gaming going on today, some content is locked until you go through the campaign mode. Like most of the items included in the freestyle amp mode are locked, and some of the minigames that can let you get some practice with different guitar techniques are locked as well.
Also, if you haven't already I'd take a look at the music library available in the game, it won't be a very fun game if you don't like the music selection.
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I am so omniscient, if there were to be two omniscience's I would be both! Prepare yourselves for the subjugation! - Ziltoid The Omniscient.