<autorever> I read about "Magic Kid GooGoo", hoping there well be a mapper for powerpak in the future too.
I went ahead and implemented mapper 190 because it looked really simple.
I played through the first level and everything seems fine so far. I don't know how the original game looks on hardware but there's some random glitchy lines, and this game seems to slow down a lot.
Source is included (based on Loopy's MMC3), but if you only want the mapper file, then go and copy MAPBE.MAP into your PowerPak folder.