Do Tails' part as usual. In Eggman's part, after you reach the check point and go through the door, you can either go down (the way to finish the level) or go to the other side. You need to get to the other side first and use his Mystic Melody (or else you might as well start over). Then, finish his part as usual. In Rouge's part, there will be a door (just search the area you start out in, you'll see it) that wasn't opened before. Go through it and use her Mystic Melody & then finish her part as usual. In Knuckles' part, you'll see platforms to climb where you'll have to use his Mystic Melody and then finish his part as usual. Now as Sonic, just go through his part as usual and eventually you'll see a path of rings that you'll have to light dash through that'll take you to the chao. --True Red
how do you get the lost chao in cannon's core? I can't find it anywhere. please help me. thankx.