Somari can be neat and technically impressive, but it's not that fun to play. The controls can be a tad finnicky, the buzz bombers that litter almost every level are a nightmare to deal with, and Labyrinth Zone is pure hell. Jurassic Boy, despite being more simplistic and much shorter, is probably a better bet for a NES Sonic clone.
Kart Fighter and the other Hummer fighters are pretty good though, and if you're into platformers I highly recommend Donkey Kong Country 4.
(Pfft, I'm bad with words today.)