Genesis Plus GX vs Retropa

Genesis Plus GX is a free, open-source emulator for Sega's 8-bit and 16-bit systems, including SG-1000, Mark-III, Master System, Game Gear, Genesis/Mega Drive, and Sega/Mega CD. It supports backward-compatibility modes and describes its CPU, video, and sound emulation as highly accurate, with cycle-accurate CPU and sound synchronization. The emulator reads raw and interleaved ROMs, as well as CUE+BIN, ISO+WAV, and ISO+OGG CD images. Emulated peripherals include 2-, 3-, and 6-button pads, multitaps, the Sega Mouse, and light guns; supported cartridge hardware includes SVP DSP, EEPROMs, Game Genie, Action Replay, and Lock-On. Standalone builds are available for GameCube and Wii, and the project lists access through frontends such as RetroArch, BizHawk, and OpenEmu. It describes compatibility with released software for its supported systems, while noting that it cannot test every game from start to finish. Some Master System games depend on particular hardware or VDP modes. The multi-platform core source is under a non-commercial license.

Retropa is an emulator for handheld and arcade games on iPhone and iPad, with Mac listed among its supported platforms. It covers 14 handheld and console systems plus arcade families; listed systems include GBA, Nintendo DS, NES, Super NES, Genesis, WonderSwan, Neo Geo Pocket, and Master System. The free plan costs nothing and includes handheld and console systems, imports, controller templates, Delta skin import, save states, and rewind. Games and BIOS files are not supplied, so users import content they are entitled to use through Files, AirDrop, a browser, a local Wi-Fi Portal, or the Homebrew catalog. Compatible external controllers and ready-made templates are supported. Retropa Plus adds arcade families, premium skins, console mode, advanced save workflows, adaptive touch controls with five styles, and 64 listed display filters. Saves can be backed up and restored with iCloud Drive. Game files stay on the device, and no account is needed to play. iPhone and iPad require iOS 18 or later.