The Genesis' launch window holds some pretty strange titles. Very early marketing for the console focused on bringing arcade games into your home, so a lot of the library in the first two years consists of ports that are watered down to varying degrees. The console exclusive games at the time are either ones with potential that are brought down by major flaws (i.e. Phantasy Star II, Thunder Force II) or some of the worst games I can think of (i.e. Last Battle, Curse). The earliest real standouts, both in late 1989, were Ghouls n' Ghosts and The Revenge of Shinobi.

The gameplay formula from the original game is expanded upon really nicely here, though it still leaves a bit to be desired that would be better accomplished in Shinobi III. Really, III does pretty much everything better, but I kinda have a soft spot for this one because it's very impressive when compared to its contemporaries at the time. A lot of the criticism directed towards Revenge is that it's just not as good as III, but if you take a second to remove the latter from the picture it becomes easier to see this is quite a solid game on its own.

I really don't like the double jump, though. Whenever I replay this it takes far too long to get used to, and it's completely required to progress as early as stage 2. Bosses can be a real pain in the neck too, but it's nothing compared to the original's or Shadow Dancer's final boss.

I would give this a go alongside Shinobi III, but preferably going with this one first. If you do III first it kinda sours this one a little, if that makes sense.