Somari and its many variants is a fascinating, if borderline-unplayable mess for the Famicom.
In a feat of questionable kindness, somebody has released a less unplayable version of the game (link in YouTube description), and I can confirm that it is a noticeable improvement over the base game. This means that as of November 2016, this is the most accurate "port" of Sonic the Hedgehog to Nintendo's 8-bit system.
That being said, Somari is a horrible game, and while this hack fixes some of the worst bits of the physics and level design, it's still inherently horrible. Still, there's hope for the future I guess!