From a graphical aspect, the gameplay in Rocky is very photo-realistic for a handheld. The GBA's color palette was definitely put to some good use. The frame rate during gameplay suffered from this immensely, which throws your reaction time off by a lot. The title interface is interesting, and there are a few cut scenes (not movies, just text and images, folks...) for the player's viewing pleasure during story mode.
Sound is also a nice touch. Voice-overs are excellent considering the abilities of the GBA speakers, not to mention sound effects. The crowds chant 'Rocky, Rocky!', as well as cheer and boo on cue, which gives a realistic edge to the game. The synthesized music from the movies is not great, however.