3DS on Steam Deck Steam Deck Press the STEAM button to view hotkeys. Combo Hotkeys using Button Chords for Cemu, Citra, melonDS (Standalone), and mGBA (Standalone). This profile is not for the mGBA and melonDS DS RetroArch cores. Emulators not listed already have controller hotkeys mapped. Mouse Inputs Keyboard Inputs Gyro Inputs Gamepad Inputs