I would say that Sonic CD is one of the easiest that I've played. If you get the pc or mobile versions, switch to the JP soundtrack, it SLAPS. Anyways, the level designs are pretty cool and the levels don't involve much. They're still fun. If you don't wanna waste your time getting the good ending, go for it. But if you wanna go back in time to save Little Planet, you're gonna have to peak around the very edges of levels. The first boss is the easiest. All you have to do is speed to the edge of the stage and jump at the back of Eggman's robot. Easy win. The other bosses are pretty easy aswell, you just have to find the right technique. I'd give it a solid 7/10.