Also known as: ワリオワールド
Spin-off of the Wario Land series and the only 3D entry of the entire Wario franchise, released on the Nintendo Gamecube and developed by Treasure Co., Ltd.
Wario, surrounded by treasures he's pilfered from all around the world and a newly constructed castle, is flipped upside down when one of the jewels he stole was actually the Black Jewel, an evil that destroyed a civilization long ago. The Black Jewel begins transforming his castle into it's own world and turns all of his treasures into monsters, making Wario vow for revenge.