The Play2CPC does not have a CTC chip, as opposed to the PlayCity which includes a CTC chip. The Play2CPC use the default configuration of most of the PlayCity programs, like ALCON 2020.
Sound capabilities are also quite different. The Play2CPC is equipped with an OPN3 (ymf288) soundchip. It offers 6 FM chans and 3 PSG chans.
The PlayCity is equipped with 2 PSG chips offering a total of 6 PSG chans but no FM chans.