Sonic in Troll Island (Beta) is a beta version of a fan-made game for Sega Genesis, suggesting it's a work-in-progress. It likely incorporates elements from the original Sonic games and introduces a new 'Troll Island' zone, implying a focus on distinct levels and game world design. As a beta release, it is an incomplete product, not officially published by Sega.  It highlights the development process within the fan game community, showing a game in its pre-release stage.

Sonic in Troll Island (Beta)

SONIC IKU DEMO