I know Parodius uses the Nemesis engine, but it doesn't belong to the saga. :/
I know it's quite a nonsense, but.... it would be really cool if someone could disassemble the Nemesis2/Nemesis3 game engine and use it to make a port of the new episodes not existing for MSX...
I know it would be very hard to do, but when I see the great disassembling job done with Snatcher (for example), I believe there's nothing impossible 
Nemesis (1) is my all-time favorit without any doubt, I finished the game numerous times (without hyper). Nemesis 2 is good and also finished some times now by me. Salamander and Nemesis 3 are no favorites of mine and I never took the effort to play those two really serious. Parodius on the other hand is a good #2 in my list of favorites. I got that one original two years ago and play it often, already finished the game but that's no reason for don't playing it again and again....
Space Manbow looks nice but hasn't the great gameplay Nemesis(1) and Parodius do have. Well, that's my opinion about the games 