Sonic Advance/Zone 2

You are now out of sunny skies and into the dark Secret Base. It appears to be another one of Eggman's factories. Get through the strange new obstacles to escape and continue the chase after Eggman.

Act 1
Let the ziplines take you to the first Point Marker. Hop onto the spring and hit the other spring to the upper-left. You should land on an iron platform, which can you bring you up to an Item Box containing a Barrier. Take the zipline here, ride the rope and jump up. Follow the path to the conveyer belt and past the gap. Jump over another gap to make it to another Item Box, then grab onto the hook. The chain will swing you over to another hook, and then a platform holding the second Point Marker. Drop down below and gain enough momentum to get up the hill and reach the Item Box up above containing an extra life. Instead of dropping back down, hop over to the platform on the left, past the Grounder and down the chute. Follow the path across the gaps, hop on the spring and to the next zipline (beware of the spring which aims to send you back down below at the end of the zipline). Ride the crane, reach the rope, and this time drop down, following the loop-de-loops to the end of the act.

Act 2
Use the iron plates at the beginning of the act here to get up to higher ground. Ride the rope above the spikes (if you're bold enough to take the risk, you can drop down and snag the Barrier inside the Item Box between all of the spikes; after you obtain it, the impact of opening the box will send you back up to the rope to continue on your route) and jump up. Get past the gap, onto the spring, and don't drop down here; use the platform to get to the other side of the gap. Grab hold of the hook and once again swing to the other side, where you should find a Point Marker. Follow the path set by the loops and gain enough momentum to reach the iron platforms, which should help you bounce up to the landing. Use the spring here to bounce up to the landing on the left, not the right, and ride the chute. Once you get out, follow the path (jumping past the gap in the middle) use the momentum of the loop to be sent up to the platform containing an Item Box. Jump across and follow the path set by the springs. Instead of dropping down after the loop, jump to the right to land on a platform with a spring. Jump onto the next spring and use the bouncy platforms to make it on top of the loop, where you'll find the Special Spring which will take you to the second Special Stage. This time you'll be starting with a goal of 70 rings. The rings won't be laid out so simply this time around, either; sometimes you'll have to follow the line of rings around the tube. Don't forget to press when you reach Trick Rings; you'll be needing those more from now on. Tag the lone chao if you can, and earn the second Chaos Emerald.

Drop down and ride the zipline into a Point Marker. With no more hidden Chaos Emeralds to worry about, get through the rest of the act to find Eggman and his latest invention, geared to knock the heroes out for good. He bounces around on a spring. Attack him when you can. Eventually, he'll spring up out of sight. This is just his way of targeting you so he crushes the heroes when he comes back down. Simply move out of the way in time (the Spin Dash comes in handy here), then continue the attack. Land enough hits and the burnt-up Eggman will flee the scene. Free the animals and move on to the next zone.