When I first played GOT, I was very impressed. My friend at the time who had a Sega CD immediately went out and bought a DUO after playing it. To this day he's a Duo fan. His favorite cartridge system is the Genesis, but his favorite CD system is the Duo - for 16bit era. I might catch some flak for this comment, but to me - the Sega Saturn was the next generation Duo/PCE-SCD. It has that Duo spirit.
Back to Duo. GOT is pretty impressive in comparison to other titles on the system, but did not push the system to its limits. The load times are short, the graphics are great, the action is non-stop, each enemy/sprite has a good amount of frames, nice use of parallax scrolls, etc. BUT, Lords of Thunder is technically superior to GOT.
For MegaDrive, I think the most impressive game for me was Gaiares - might be my fav shooter of all time. Gunstar heroes and ThunderForce4 are in the top list. Exranza had some impressive parts, but not overall. I wasn't impressed with Revenge of Shinobi - I perfer Ninja Spirit over it even though they are completely different games.