If you wish to own certain digital versions of classic Sonic the Hedgehog games then you may want to grab them soon as Sega will be delisting them.
The company announced today that digital versions of Sonic the Hedgehog 1, 2, Sonic 3 & Knuckles and Sonic CD will be delisted from digital stores on May 20, 2022. There will be a few exceptions with those being Sonic the Hedgehog 1 and 2 via the SEGA AGES line on the Nintendo Switch and Sonic the Hedgehog 2 via the Sega Genesis app on Nintendo Switch Online + Expansion Pack.
Sega is most likely doing this because the above games will be part of the Sonic Origins game that is launching in June. Still if you don’t want to buy that and would rather own the games standalone you have less than a month to buy them.