Identical to the (E) version in core gameplay, Catz (U)(Rising Sun) offered the virtual pet experience to US audiences. Players likely engaged in similar activities, such as feeding, playing with, and caring for their digital cats.  The (U) designation specifically highlights the US release, suggesting that regional differences were minimal, if any, in terms of gameplay mechanics or content.

Catz (U)(Rising Sun)

Castleween (E)(Eurasia)