Give them a shot. Start with BoD7, since it explains a bit about the game's mechanics, which are the same for both. If you start with Cthulhu (as I did) you may be somewhat lost for a while. No big deal, though.
They're spoofs of 80s console RPGs like Phantasy Star II, and play as such. I'm not a fan of random battles, and the humor only gets me to tolerate them for so long.