プチコン (Puchikon) was only released in Japan. This version didn't have BGM, (I think) and didn't have the QR Code scanning function. You had to program it to have it.
プチコンmkII (Puchikon mkII, known in North America as Petit Computer) was released in Japan and North America this included BGM and the QR Code scanning function.
3そうだね 未プレイ