According to ESRB, this game contains: Animated Violence, Mild Language
As successful as Pokémon was, it has always lacked a compelling story or the sophisticated graphics to hold the interest of older players. Genki took notice and when they produced Jade Cocoon, they intended to come through in a big way. Genki abandons Pokémon's large sprawling story line (with a multitude of side stories) for one that could best be described as quaint.
In terms of actual gameplay, JC isn't quite the sprawling trek that most RPGs represent. Instead, traveling is minimized through menus and plot devices that enable quick entry to particular areas. There is some exploration, but the main focus still resides on combating and capturing monsters (as Dale already mentioned, unoriginally dubbed Minions).