The Towns has nothing to do with the PC-98, at least not directly. They're both X86 based systems that were incompatible with the western IBM PC standard. The Towns is derived from Fujitsu's FMR series for which very few games exist, they were really primarily used in businesses. The home computer line before the Towns was the FM7/77 series, so it's essentially a successor to that.
The console variant (Marty) won't give you access to the entire games library, because it doesn't allow the necessary expansions (RAM, HDD, the CPU is also the weakest in the line), though maybe people have found ways around that, as they often do. Then again, it's such a niche machine, and the games library isn't that hot IMHO.
Emulation is somewhat bleak, UNZ works but is old and not open-source, the MAME driver is functional to an extent. There's was also Marty support in the now defunct multi-console emulator XE.