The Retro Boy is a Game Boy emulator developed in Rust and designed for web use, which allows users to play classic games without requiring a traditional desktop setup. User comments highlight the potential issues like audio clicks during gameplay and performance differences across browsers (e.g., it works well on Chrome but slow in Firefox). There is also excitement about the ease of sharing these emulated games online, as users can access them simply via a link, showcasing the benefits of web assembly (WASM) technology. Several comments express enthusiasm for the project and a desire for additional homebrew ROMs for more gameplay options.