Its all a bit weird really. I have a 101 in 1 that I sent to cah4e3 with one original game, F-22, credited to "Inventor". the rest of the games are hacks, including some of the ones on the Yarou etc, but one of those also has an Inventor copyright (ironic really). which made me think Inventor was actually responsible for the hacks. (maxzhou88 also posted an Inventor graphics editor on his blog, which I'd guess would be what they used to make them).
but if that was the case, I doubt Inventor made any of the originals on the Yarou (or the D-Cat, or other stuff), because F-22 is completely different in style, has reasonable music and is far more advanced than those originals, despite being from 2001.