Fist: the MjoySetup (configurator) and firmware should have the save date.

The latest version of both is in the package "MJOY2 [v20161101] .rar " (November 01, 2016).

https://sites.google.com/site/mmjoyproject/fajly-dla-skacivania

Bootloader leave Arduino ready to receive the firmware uptate - during 8 seconds. smile
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For transfer the firmware used MjoySetup.exe - tab Firmware (as in F15Sim instructions or there https://sites.google.com/site/mmjoyproject/prosivka).

Done this Arduino became a HID (Human Interface Device), and use Windows native drivers.

And the "joystick"?

Is the "MMJ-Reset" you see in MjoyStup.exe,

Don't has buttons or axis because is your option set how many buttons/axes want, as well what "joystick" name (up to 10 characters, I think), after choose use the button "Save Settings for Device" (and ca reconfigure when want).