Nerdbox can use a USB mouse to emulate the SNES Mouse, made popular with Mario Paint, as well as the Zapper Gun for the NES. To do this, you will need a standard, wired USB Mouse.
NES Zapper games will be supported without any work. To be fair, I only tested it with Duck Hunt, and that asshole of a dog made me stop.
SNES games require a little setup. You will need to do this setup once per game.
• Find then start the SNES game that you wish to use the mouse with
• Press Select+X to access the configuration Menu
• Go to Quick Menu \ Controls
• Change "User 1 Device Type" to SNES Mouse
• Press B to go back
• Select "Save Game Override File"
This should enable the mouse in the current game, if the game supports it!