For all those in the US, Sonic Gems might be… “lacking”. Basiclly, the Streets of Rage Trilogy does not confer with the E rating, so its been omitted from the US version. Why they couldn’t change the rating is beyond me.
It’s unknown whether the PAL version will include this ommission. However, we can expect Vectorman 1 and 2. If you’re wondering why Sega doesn’t add Chaotix and SEGAsonic instead of games few of us have heard of, you’re not alone.
By the way, the Sonic CD soundtrack is the US version and there may be game improvements, such as team battles in Sonic Championship.
Scource:Sonic News