Game cartridge only. 200 Hot games in one cartridge for Megadrive and Genesis consoles. 100 of the best games for both each Sega Master System and Sega Genesis/Megadrive. Battery save function works for all games that require battery save feature. The pictures of the full game list also shows which games have battery save function. Please look at pictures for complete game listings. Note: The top 100 Master Games only work on NTSC version Megadrive/Genesis console. If your console is PAL version, then you can not run the Sega Master System games but only the Megadrive / Genesis games. FUNCTIONALITY COMPATIBILITY Works perfectly in an original Model 1 or 2 Sega Genesis or Mega Drive system. Mini Gen, Retron 3, Retro Trio, Genesis 3 and RetroAD systems also work perfectly. Nomad handheld systems will have many incompatibilities and are not recommended. Retron 5 WILL NOT WORK - it is an Android emulator, not hardware, and cannot load multiple files. ATGames systems WILL NOT WORK. This means the Classic, Flashback, etc. They will only ever load one wrestling game and no menu. If you have one of the newer tiny systems with 80+ built in games, that is an ATGames system and WILL NOT WORK! All games are full versions. In-game codes and passwords work like you remember.