Play Konjiki no Gashbell!! : Unare! Yuujou no Zakeru Online

Konjiki no Gash Bell!!: Unare! Yuujou no Zakeru came out for the Game Boy Advance in 2004, published by Banpresto. It was part of that wave of mid-2000s anime tie-ins that tried to capture the spirit of a show in a portable format, and it stands out for sticking close to the source material without trying to do too much.

You control Gash and his human partner Kiyomaro, exploring areas screen by screen and getting into turn-based battles on a grid. The main goal is to fight other demon children and their partners to become the king of the demon world. The signature mechanics are shouting spell names into the microphone at the right time to power them up and managing your limited spell uses before needing to recharge. The pacing is brisk, and the difficulty can spike during boss fights if you haven't mastered the timing of your shouts. It feels like a faithful, hands-on extension of the anime's battles.