A lot of Topaz's story is centred around the conflicting motivations of Simon, Bradley and Vincent/Alisa as well as looking deeper into the underlying motivations of Giovanni and Ophelia as team leaders. I don't think there are really any heartwrenching tearjerker moments but from my experience reading the script there are some pretty nice "aha!" moments with regards to learning about some characters, especially Simon, who drives the story the most. Irot_Rebod has composed some incredible music for the opening scene but for the most part the soundtrack is the catchy atmospheric music found in other Pokemon games that sets the area rather than specific story moments.

Hope I answered your question!