After choosing a guitar, difficulty and a song you can begin the game with the Ready button. Commands will move across the screen, the aim is to press the corresponding key when the command reaches the time bar. Each correct command gives you 10 points, but pressing a key at the wrong time will cost you 10 points, so don't button mash. Collect combos to increase the multiplier. There are also hold commands that will give you more points the longer you hold the key. Use the ARROW KEYS and "A", "S", "D" KEYS (hold). A good score you will get you an award which will go towards unlocking new stuff.