Hikou no mizu (?????) is a free platform-based fighting game, licensed under the GNU GPL v3 (program) and the LAL (graphics). It works on many operating systems including GNU/Linux, *BSD, Haiku, OS X and Windows.
The characters use natural powers such as water or lightning, but they can also (mostly for now) fight the traditional way!
The name "Hikou no mizu" (pronounced "Aiku no mizu" comes from japanese, it could be translated by : "Hikou's water", Hikou being the main character of the game.
Hikou no mizu is a free (as in free speech) software. It's licensed under GNU GPL v3 for sourcecode and LAL for the multimedia part of the game (graphics, sounds, ...).