This deck of playing cards is likely rare. As you can see here, it's an early item, due to the "Segasonic" name/branding, which they phased out of use forever in the mid 1990s or so. This deck is still in the original clear plastic package (though it came in a plastic hard case, originally) What do each of the cards look like? Are they all di fferent, featuring screen shots like the ones seen here? Write in if you know!
A Green Hill screen shot has some seldom-seen Sonic art on it (is it a 'cover card' or are all card backs like that one?) The art shows Sonic looking at a racing helmet. It is originally from the Sonic screen saver / Sonic wallpaper set (image 51) which was done by a Japanese artist with a very specific style.
The Joker card is revealed on the bottom, it shows Spring Yard, but has ordinary 'running Eggman' stock art placed over it. As you can see with the sticker, this was made by Sanrio (yes the Hello Kitty people make cards too) & "Angel Playing Card Company of Osaka Japan". An interesting deck!