The second rule of Hamster Club... no, wait, this was the first game. And while the characters are the same ones that appeared in the puzzle-stacking Awasete Chu, here, the goal is simple: WIN THE HAM'S CUP. Through the development of a training regime, managing care and feeding, and occasionally causing your hamsters to freak out at the sight of toothpaste (yes, that's actually a thing), they'll grow stronger and faster. All the better to bring home the GLORY OF THE HAM'S CUP.
The interaction takes place primarily in training, as the actual events may or may not allow for direct control of you hamster. As such, you must make them wise as well as fit (and fluffy and adorable, because HAMSTERS) so they can navigate their own way when the crunch is on. Or, they might win just by sitting there and being cute. That works too.