Jurassic Boy

Jurassic Boy is an unlicensed bootleg platformer vaguely imitating Sonic the Hedgehog. It stars Chen the Dinosaur, whose family was abducted by the time-travelling Dr. Crachi. The game features a ring loss system similar to Sonic, and some loops to run through, but otherwise does not play much like the Sonic platformers, e.g. lacking a rolling move or a spindash. Some of its seven stages have branching paths and multiple exits, which can take you to different stages (with one exit even going back to the first stage). The Game Boy Color version adds boss fights at the end of every stage.