S3&K tends to be the game(s) I found most boring of the 3. It's hard for me to say exactly why. I know I didn't like the soundtracks and artstyle as much as the others, and this tends to be a bigger thing for me than it should. Maybe this could be seen as the turning point of when they started to not "keep it simple, stupid," that led to the Adventure series with a clusterfuck of characters and game play styles and not enough polish, except Sonic 3 had polish and a reasonable amount of character choices. I think it more had to do with some stages feeling more tedious than anything. I guess I kinda liked Angel Island zone. I found Hydrocity Zone boring. I found Marble Garden to be boring and it's boss tedious to control. I found carnival night to be annoying. Ice Cap was fucktons of awesome. Launch base was meh with some fun bosses. Thought Mushroom Hill was boring and ugly, though I did like the season changing in Act 2. I thought Flying Battery was really fun with a lame boss. Sandopolis was meh. Lava Reef/Hidden Palace were pretty cool. Sky Sanctuary was pretty awesome, as was Death Egg. Doomsday was cool at first but later just becomes an unwelcome gameplay change. The thing is, I am having trouble exactly pinpointing why I don't like the levels I didn't like... Except maybe Marble Garden and Carnival Night. Also, this.