I decided to do quick search of existing rhythm-based fighting games and this is what I turned up, with regards to commercial examples anyway:

There’s Zen Studio’s Kickbeat, which uses its sound track or takes whatever music input you provide and coordinates a series of instantiated would-be challengers to attack you on the beat, unless you smack them down first, which you do by providing the correct input based on the enemy’s color and position.

SNK Playmore’s The Rhythm of Fighters in which you link inputs together to create combos. You have some decision making in that you can block, but it seems mostly to be input matching to a beat.

Then there’s this unexpected item, developed by 505 Studios (?), Way of the Dogg is some oddball game that revolves around input combination to the rhythm of Snoop Dogg/Lion’s opus of rap songs. Very strange indeed.

All of these games look like they take Guitar Hero or DDR are as their inspirations, which is cool, but it just frames the rhythm recognition/input combination mechanics as fighting rather that music making or dancing and so the strategic layer that you find in fighting games is pretty thin. Also, it doesn’t look like any of them have a multi-player element. What we are trying to do with Rhythm Fencer is to preserve that decision making/strategic element, while requiring the players to be on a persistent beat. I’m sure other games must have explored this concept. The research continues.

– Bob

Sources:

Kickbeat Review
The Rhythm of Fighters Review
Way of the Dogg’s Website