Guitar Flash is a musical game, similar to Guitar Hero, where you try to play songs perfectly by hitting the right notes as they appear on the screen.
Before you start playing a song, you can choose between three different difficulties. If you choose easy, you'll have three notes to play; if you choose normal, four; and if you choose difficult, five. Of course, the more difficult the mode, the more points you'll get as you play. Some songs are incredibly hard to play correctly on difficult, so make sure you're really ready.
When you start, you can only choose from four songs. As you play, however, improving your score and getting coins, you can unlock new songs. You can unlock more than a dozen different songs in total.
Guitar Flash is an excellent musical game that'll probably remind you a lot of Guitar Hero, only this version is perfect for touch screens. The game doesn't take up too much space, either, coming in at less than 40 MB.