If you've played
Guitar Hero before, you will instantly recognize the menus and know exactly what you're supposed to do. You have the options of Career, Quick Play, Multiplayer, Training, and Options. If you've never played
Guitar Hero before, you might want to run through the Tutorial. You'll be given the basics of the game from a man that sounds like an MTV VJ for Headbanger's Ball. The basic concept of
Rocks the 80's is to play the notes you see scrolling on the screen. To play a note, you hold down the color button that corresponds to the note and the screen, and then strum the strum bar to the beat. Sometimes, you'll notice the notes are star shaped. If you perform those perfectly, you'll earn Star Power. To activate Star Power, tilt your guitar neck up, and you'll be given double the points until it runs out. The Training also has a section called Practice, which allows you to choose any song you want to play or practice on. The practice feature is really nice, as it allows you to choose a song and a difficulty level, and slow it down so that you can get the right finger combinations and learn how to play it on a slower speed. It really helps on those boards that you just keep failing on the same section every time.
When you choose Career, you're given the option of Easy, Medium, Hard, or Expert. If you've new to the Guitar Hero series, start with Easy. You won't earn any money until you go to at least Medium, though. From Medium through Expert, you earn money based on how well you perform a song. The money can be used to purchase new characters (well, one new character), new guitars, and different finishes for your guitars. The only difference in Career and Quick Play is that in Quick Play, you're free to play any song you have previously unlocked, but you don't get any cash for your performance.
Multiplayer is the same as it was in Guitar Hero 2. Each player can set themselves on a different difficulty level. You have the option of Cooperative, where you and a friend play together to try and get the highest score combined. Most of the time, one is playing bass and the other plays guitar, though some songs you play lead and rhythm guitars. You also have the option of Face-Off, where you are playing against each other, with alternating sections to play. You don't play at the same time. The final option is Pro Face-Off, where instead of alternating back and forth playing, you're playing the same notes at the same time to see who can get the better score.
If you want to change any of your game configurations, you choose Options from the main screen. Inside Options, you can configure your audio settings, video settings (including setting the guitar for lefty players), manage your career bands, check your data settings, watch bonus videos, and watch the credits.