Frets on Fire is a Finnish music video game created by Sami Kyöstilä in which players use the keyboard to play along with scrolling on-screen musical notes to complete a song, and is a clone of the Guitar Hero video game series. Frets on Fire is open-source software.

The gameplay of Frets on Fire is the same as in Guitar Hero - the player emulates playing a guitar. Frets on Fire is meant to be played by picking up the keyboard like a guitar, with one hand pressing the fret buttons and another pressing the pick buttons. There is support for joysticks however, meaning that the Guitar Hero controllers can be used as well.

Colored markers appear on the screen, synchronized with the song, and are played by holding the fret buttons of the correct color (F1 through F5) and pressing one of the pick buttons (Enter or Shift) at the correct moment. Every ten correct hits increase the score multiplier, which multiplies the points for every hit by up to four times. The multiplier is reset in case of a miss.

Since version 1.2.438, the game features hammer-on and pull-off (commonly abbreviated to HOPO) notes. A HOPO note allows the player to press only its fret button to play if the previous note was played correctly. Bugs were found in the new gameplay element, and version 1.2.451 fixed them, along with adding an option to disable HOPO notes.

Features:

- Three default songs by Tommi Inkilä, along with the ability to import songs from Guitar Hero and Guitar Hero II and add songs made by others; Also one done by Scenery Channel officially for FoF, downloadable from their website
- Unique inverted keyboard gameplay style
- Support for guitar controllers and generic joysticks
- Includes a song editor for making your own tunes
- Compete with others on the World Charts
- Hundreds of songs composed by the community
- Supports importing Guitar Hero™ I and Guitar Hero™ II songs
- Multiplatform; runs on Windows™, Linux®, Mac OS X™ and FreeBSD®
- Open source, full Python source code available

Get it here: Frets On Fire