"Are fake ds cartridges playable"

today I purchased pokemon soulsilver on ebay and quickly realised it was fake, decided to check my other pokemon games as well and found out that my pokemon platinum and pokemon pearl were fake. are they still playable, are there any differences? ive been shiny hunting on the platinum for the past few days as well and dont want to learn that i cant get shinies on it or something (also i kinda feel bad for my parents as they were the ones who got them for my birthday 3 years ago, dont want to just tell them they bought fake ones) via /r/pokemon https://ift.tt/3qOrDh7