Altered Beast ROM Download for Sega Master System (Sega Master) on Emulator Games. Play Altered Beast game that is available in the United States of America (USA) version only on this website. Altered Beast is a Sega Master System emulator game that you can download to your computer or play online within your browser. You can also download free ROMs such as Altered Beast (JU) (REV 01), Altered Beast - Guardian Of The Realms and Altered Beast (USA, Europe) as shown below. Altered Beast works on all your devices in high quality.