Well from looking at it, the first pic shows it's pixel quality, which is a lot lower in quality than what you would find on a normal tamagotchi connection or tamagotchi plus. The infrared connecting spot on the top of your virtual pet is also the wrong colour. It's pink and not red.
I've had this kind of fake before and it isn't bad, but obviously they put a cheap microchip into a real shell since it still says bandai on the back. Tell us more about the gameplay so it'll help with determining without a shadow of douct it's not a real bandai pet please