Let's pretend for a second Nintendo R.O.B. is a handheld, then I can post about it here.
Sean dumped a couple of Sharp SM590 MCUs in 2017(eg. NES/SNES lockout chips), and Lord Nightmare (the guy above me in this thread right here) started writing SM590 emulation as a subdevice of SM510. Last week after I worked on SM530/Nelsonic stuff, I finished MAME's SM590 emulation, and added the ROB that also uses a SM590.
It uses a similar lightsensor as the NES Zapper, so I don't think it would have worked were it not for kmg's recent improvements on that.
It's even more useless than the real ROB since the physics are not simulated, but may be fun to try once.
mame nes gyromite -special rob -numscreens 2