Play Arle no Bouken - Mahou no Jewel (Japan) Online

A monster-collecting RPG set in the Puyo Puyo game world and starring the young apprentice magician Arle, who must explore the land in order to collect a series of magical gems and defeat the evil Satan, who plots to take over the world yet again.

The game is played from a top-down perspective in which you control Arle as she explores towns and dungeons, chatting with NPCs, finding or buying items, etc. Combat whisks your character to a side view from which you select your actions in standard turn-based fashion and fight it out against the many monsters and opposing characters that you can run into. Whenever you defeat a monster, you gain their unique card which can be tapped to summon said monster to join you in your quest. You can have up to two monsters fighting by your side at any time, and they level up and gain experience just like you do.