On act 2 run right until you come to the trampoline that has a cart that will take you to the goal. Bounce on it and press left. Go up there should be a super ring there. Roll off the edge untill you hit a cart that. Jump off at the edge and run right.

Sky high

This one's tricky. On the first kite fly up til the end.(you might miss but you can go back and try again)

Aqua lake

At the end go into the tubes while pessing the button between the left and down direction. You'll go into a room with spikes at the top and an emerald.

Green hills

On the 2nd slope run down and bounce on a set of trampolines. Hold right until you hit another set. Then hold right for about 2 seconds.

Gimmick mountain

Go to the part where the badnick is at. Kill it and jump through the wall. jump the spikes and get the life. bounce on the tramp and fly up on the wheel. Get the other life and the wheel. Run right until you find the emerald.

Continues
For every 2nd act on Sonic 2, there are secret crystals that will get you 3 extra lives. You usually have to find them between gnooks and crannies. When you die and get a GAME OVER, it will ask you if you would like to continue. Then it will let you play again with 3 lives to start with on the same level you died on.

Extra Life
In act 1 of underground zone, jump over the hole, roll down the hill, and on the spring that comes next, jump on it and press LEFT. You will be walking on the bricks and then you will fall in a little space and there in a life there.

Extra Life (level 2)
After you fall down to the water go left and jump into the wall. You might just want to take a half jump to fit in the secret hole.

Level Select
To unlock level select, push the d-pad LEFT at the opening intro (the one that says “Sega”) then simultaneously press button-1 and button-2 when Tails winks his eye the third time. Now push Start.

Skip Through Water
On Aqua Zone act one to skip through the water run and do yhe spin move (run and push down), and then you'll skip through the water. This also works on act two.

Sometimes They Come Back ...
On Scrambled Egg Zone act 2, follow the route as nomal, and in the second pipe section, go right, then left as normal, then up to enter the bonus section. Get over to the area with about 100 rings by spindashing. You will skim over the ground, collecting an extra life. Collect the rings and go back. The extra life will have reappeared!

Unlimited Lives
There are two 1-ups in Act 1 of the Sky Hill Zone. To get to the first one, pass the bridge, jump over the two sets of spikes, ignore the Ring Monitor and the spring. Finally, jump over one more set of spikes to grab the 1-up. Go back and jump on the spring, then walk into the horizontal spring, which will roll you through the bricks. You'll reach two more springs. Jump on the vertical spring, and you see another spring. Jump on this one, and hold left on the directional pad until you see a patch of ground with Christmas trees in the background. You'll then see another 1-up. Take it, let yourself die, and then repeat this process until you max out on lives.