Vattroller X

Vattroller X is a Action RPG released in 2004 for the Game Boy Advance. It's based on a V-Jump manga.

Battles in the game are played in real time from a top-down perspective, not unlike Zelda. You can attack with your equipped weapons and perform small combos, rushing and charged attacks. When a character runs out of HP, it turns into a ball. Whoever manages to knock the ball into a pit scores a point. While in ball form, characters can roll around and dodge attacks until the normal form is recovered. Succeeding in this, however, cuts a part of the character's life bar, making continued survival more difficult.