The aim of the game is to play guitar with the keyboard as accurately as possible. Frets on Fire is open-source and includes: a unique inverted keyboard gameplay style; support for guitar controllers and generic joysticks; a song editor for making your own tunes; the ability to compete with others on the World Charts; hundreds of songs composed by the community; and support for importing Guitar Hero and Guitar Hero II songs.
The main mode of play in the Guitar Hero games is Career Mode, where the player and in-game band travel between various fictional performance arenas and perform sets of four to six songs. It is by completing songs in this mode that the songs are unlocked for play across the rest of the game. Players can choose their on-stage character, their guitar of choice, and the venue they wish to play in. In this mode, the player can earn money from his/her performances that is redeemable at the in-game store, where bonus songs, additional guitars and finishes, and bonus content can be unlocked. Quick Play mode is a quicker method of playing songs, as it allows the player to select a track and difficulty, selecting the character, venue, and guitar and guitar skin for the player based on the song chosen. After successfully completing a song, the player is given a score, a percentage of how many notes they hit and a rating from three to five stars, and two in rare cases depending on his/her final score on the song, with money being awarded in guitar hero world tour.
The games have also added multiplayer modes. Cooperative modes allow two players to play lead and either bass or rhythm guitar on the same song, working together towards the same score. A competitive Face-Off mode allows two players to play against each other at different difficulty levels, each attempting to earn the best score on a song. Each player plays different portions of the song. There is also a Pro Face-Off mode, where two players battle at the same difficulty level. Unlike standard Face-off, each player attempts to play all of the notes in a song, while still trying to earn the highest score. Guitar Hero III introduced Boss Battles, in which two players face off against each other, attempt to collect “distractions” to throw at their opponent, trying to make them fail. With Guitar Hero World Tour, up to four players can play cooperatively on lead and bass guitar, drums, and vocals, while a total of eight players can compete in a Battle of the Bands. The Xbox 360, PlayStation 3, and Wii versions of the games support multiplayer modes over their respective network services.
The four difficulty levels for each song afford the player a learning curve in order to help him/her progress in skill. The first difficulty level, Easy, only focuses on the first three fret buttons while displaying a significantly reduced amount of notes for the player to play. Medium introduces the fourth (blue) fret button, and Hard includes the final fret button while adding additional notes. The addition of the orange fret button forces players to move their fingers up and down the neck. Expert does not introduce any other frets to learn, but adds more notes in a manner designed to challenge the player and to simulate the player’s hands to move in a sequence similar to a real guitar. A difficulty added in World Tour is Beginner, which only requires the player to strum to the basic rhythm; holding the fret buttons becomes unnecessary