Shaq Fu is hanging for some reason, but I guess it's related to the sprite OAM stuff...when the game starts to do a DMA to the OAM port the game'll hang for some reason. Indeed a debug trick (by trigger random values to "zero-page" address $84 when it hangs during attract mode) shows the following screen...
...attempting to write more causes graphics artifacts with the (incidentally) sprites...ideas?
As for Rock N' Roll Racing, it's definitely un-initialized palette RAM, if you wait an attract cycle it puts the following:
It does this:GDMA-Ch 3: len: 10000, abus: 7E2200, bbus: 2122, incr: 1, dir: CPU->PPU, type: 0
For non-experts: BBUS 0x2122 is the cgram port, cgram size is 0x200 and 0x7e2200 is null data. Pratically these are the DMA params modified by a previous DMA, if I remove the hook-up colors are right (i.e. if I keep the params to be abus = 0x7e2000 and length = 0x200). Still searching for a explaination (timings or a DMA quirk?)