Exodus has a decent enough VRAM viewer:
You need to piece stuff together, but it does get the palettes for you automatically which cuts out some of the work.
Ripping all of the sprites directly from the ROM is, of course, just as difficult a task as with any game from a console without a filesystem. Not sure how much I can help in that regard.
But yeah, Sega Pico games are pretty much identical to Mega Drive games, so you'd approach them in a similar way.
You need to piece stuff together, but it does get the palettes for you automatically which cuts out some of the work.
Ripping all of the sprites directly from the ROM is, of course, just as difficult a task as with any game from a console without a filesystem. Not sure how much I can help in that regard.
But yeah, Sega Pico games are pretty much identical to Mega Drive games, so you'd approach them in a similar way.