The in-game menu allows you to insert disks/tapes, load them and configure the display, joystick ports etc. Saves will be stored on the SD card. You can save and load game state. When you save the game state also some preferences are saved in the state (joystick buttons, screen format, joystick port, 1541 emulation, rumble). The whole set of preferences is saved from the main in-game menu and it is loaded on Frodo start-up. Wiimote 1 is by default the joystick in port 1 and wiimote 2 the joystick in port 2, but you can swap this. If rumble is enabled, the wiimote rumbles each time the fire button is pressed.
For full detail http://wiibrew.org/wiki/C64-network.org