Nah, doesn't seem to be. Its not compatible with OneBus PJ cartridges either.
And then theres the Subor plug & play, which is... weird. That little wheel on the thing, I thought would be to control driving games, but it actually just lights up with 3 LEDs which flash constantly. It does have a cart slot at least. But it's battery only, and it suffers from the same audio interference problem as my Super Gun King, which you can see in some of the videos on my neopnp channel. D:
As for the built in games, theyre all Waixing/NC stuff, nothing I haven't seen before so far. Unusually for Subor its not a VT03 though.
and finally - the dance mat. it has "Panasonic Tau" branding on it, which was a line of TVs they sold around 2000 or so, which makes absolutely no sense. I'll try and get a picture of this thing at some point anyway. My theory is that, I guess, some Taiwanese Panasonic distributor had it made as a promotional item? Otherwise its just your standard dance mat Famiclone, the built in software is pretty much (if not completely) identical to one of the dumped DDR-clone ROMs.
Also it runs off an AC adapter only, there's a battery cover on the back which broke when I tried to open it, and then I discovered there werent any connectors for the batteries anyway. Quality stuff, this.