Again, head right through the corridor on the other side of the last big ring and you'll emerge from a curved route to rejoin the end of a vine pathway. Keep heading down the slope, through one loop, but then the following vine pathway will lead up but then flip back to the left, winding up to the path via a red spring. You need to avoid going along with it, and instead jump off when it starts heading left, and walk off of it to drop down to the right. If you're too slow and end up taking the spring upwards, just drop off the platform to the left and try again. Shortly after, you'll find this room on the lowest route, which later rejoins the normal one to go straight into the boss.

As Sonic, following on from Point #1 and for S3&K players only, before you return to Sonic's ordinary starting point, you can spring up to a high platform in a brief internal section, past a Dragonfly to a couple of ten ring items. What you may not realise is that this little platform actually allows access to a series of other platforms and high up pathways dotted across the top of the first third-or-so of the act, which otherwise would have remained completely inaccessible. Granted, there's not much of interest on this route other than an invincibility item, some extra rings and a rare Eggman item you may never have realised was there at all (although purely look-but-don't-touch - it causes you to take damage if opened!) but it's nice to explore. From the platform with two ten ring items, all you have to do is spin dash (give it quite a few revs though!) to the right, from the left side of the platform, allowing yourself enough space to jump off of the end, thereby giving you the speed and height to make the next one. Springs, ramps and swings will take you the rest of the way.

When he tries to cut down a fifth piece, in Sonic's fight, his axe will get stuck in the stump. He'll exert some energy trying to pull it out, and when he finally does, this will cause him to be thrown back, and bounce along the ground to the left. He'll then hover back up and repeat the process, moving onto a new tree trunk further on to the right. For Knuckles, he actually does chop down the fifth piece, but obscurely, he also loses his head in the process, which bounces across to the left with it. It'll blast back up to the body, which is floating on the right side, and he'll then sweep the middle of the ground, then fly back off to the left and restart the pattern. This may all seem fairly complicated, but dealing with him is easy. Just hang out in the bottom right corner, directly beneath him, where you'll be perfectly safe from all the logs. When he's facing right, just keep jumping and hitting him, but watch out for when he turns his back to you, because then you may collide with the small flames from his jet pack. Deal him six hits, preferably before he moves down to the bottom of the log and even begins the second phase of the attack. A fire shield is handy to avoid the flames.

An easy one. Near the end, right next to the pump device of Point #8, the corridor that leads to the ring is guarded by a Cluckoid. Use the pump handle to negate the breezes he generates, then take him out and stroll into one of S3&K's most obvious big rings.

If you're having trouble, there is another option. From the swing, try going left a little way, back through the corridor and out the other side. Stand to the right of the first set of floor spikes that you see, and hit a powerful spin dash toward the curved bit of the path to fling yourself up to the ledge above, whilst holding right when in the air. On this higher path, you can carry on right, and straight over to the spring.

After the last checkpoint, you'll see a satellite sitting on top of a step, emitting electricity up to the sky. I've no idea for what purpose, but just go with it. Jump and hit it, and it'll start exploding, and a brief bit of white light will transform the Winter area back to Spring/Summer again. Out of the ground will emerge Robotnik (or Eggrobo if playing as Knuckles), in a fairly odd looking large blue machine, with twin fire-blasting jets at the front. If you want to be done with him as quickly as possible, snag as many cheap hits in on him as you can now, because he's about to blast off out of the screen! Follow him over the hill, and you'll find that rather than mounting an effective offense, he's actually retreating, flying backwards above the ground as the screen scrolls with him, pushing you forward. You still have the ability to run and jump around the on-screen area though as you chase down your nemesis, landing hits on him at every opportunity, just about anywhere on his machine. However, in addition to the harmful flames periodically produced from the small front-mounted jets, you also have to be concerned with the series of orange posts that you're running between, lining either side of the path. Each pair of them has a string of small spiked balls linking the posts together, and they're at varying vertical positions, so you'll have to leap over some, and run underneath others. For some of them, Knuckles has to actually jump between two strings of spikeballs on the same pair of posts, so ensure that your jumping accuracy is top notch for those. Also be aware that if you lose your rings, it's sometimes tough to re-collect any as they'll fall to the left side of the screen and out of the area, and there are no additional ones during the boss fight. After eight hits, your foe's craft will burst into flames, as auto-pilot kicks in on your character, running him through the small doorway of a giant tree trunk, while Eggman just crashes into it. This is the first of many bosses in the series to be fought on-the-run in this way.

After freeing the animals and all that jazz, Sonic or Knuckles will start to hear a noise from above them, and look up to see the Flying Battery, Eggman's latest flying battle and prison ship, hovering just above. There seems to be one of those mole badniks sitting in a sort of hanging cockpit for some reason. Eggman/robo then flies off with it, attracting the attention of your character who then runs further along the platform in hot pursuit, eventually leaping and grabbing hold of it, in order to sneak onboard..