These taxman-backed remasters were gold standards. Sonic 3 & Knuckles was delisted in 2022 due to music licensing issues (Michael Jackson’s unreleased tracks). If you bought it before delisting, you can redownload it. If not, only Sonic 1 and 2 remain available for purchase via the modern store.
Previously purchased DLC (like the Unleashed Adventure Packs) and mandatory game updates remain available for download through your history. 2. Purchasing New Digital Copies sonic xbox 360 download