GC-Inside reported that the Japanese developer Tommy has announced plans to release Mutsu: Water Looper for the GameCube on June 28th.

Mutsu: Water Looper is the second announced GameCube work alongside Zoids Versus from Tommy, who confirmed it was working on five other projects (besides Zoids Versus) a few weeks ago.

The only thing currently known about the game is it's based on the adventures of underwater life. Tommy will reveal more details on the game very soon.

Source: N-Sider.com, GC-Inside.com