Bonus points:
Try to finish at a time of 9:59. You will be rewarded with 10,000 points.

Hyper Sonic:
Enable the "Level select" code. Press [Ctrl] + R. At the menu, scroll up one to "Sound test", enter it and select "Special Stage 2". It is fairly easy. Complete it and you should be at Angel Island. Repeat this seven or eight times as Sonic. The seventh Super Emerald (you cannott see them) should say "Sonic got all the Super Emeralds". Collect 50 rings and Spark Sonic. Press (Jump) two times and you should become Hyper Sonic.

Screen shot:
Press [F9] during game play.

Quick start:
Enable the "Sound test" code. When you restart the game and enter the sound test menu, highlight the Special Stage 2. You should end up in a Emerald Sphere Challenge with slightly different music. Collect the blue spheres and you should receive a golden Super Emerald that will start you off with two Chaos Emeralds. If you get a Perfect, you should also start off with 54,800 points. Note: This game cannot be saved.

Free bubble:
After you defeat the first Boss in Angel Island, (get a fire shield and hit him under or jump on him once while on top of him) do not hit the sign up to get a 100 points. You will usually get a bubble and can now go underwater.

Super Sonic rings:
Once you maintain Super Sonic, it will say clear at the end. Go to a huge ring and it will automatically give you 50 rings. Now just jump twice and you can go very fast and jump very high.

Knuckles' big afro:
You can use the sign to make Knuckles appear to have grown a lot of hair. It is done the same way as Sonic's afro trick, except that he faces the opposite direction and stands slightly more to the right.

No ending:
Enable the "Level select" code on Zone 1, then Zone 7. Play as Knuckles on any level. Press [Alt] + R. Select the Doomsday Zone, Act 2. The name will appear as Death Egg Zone. Defeat the Doomsday Robot, and the game will return to the main screen, with no ending.

Level select:
Select "Sonic & Knuckles", choose any character, and play Zone 1, Act 1 (Angel Island). Jump and hang on a swinging vine. Then, press Left, Left, Left, Right, Right, Right, Up, Up, Up. A sound will confirm correct code entry. Press [Alt] + R to restart the game. Press [Down] [Down] and select the sound test. You can now play any zone with any character. Note: 00 = Sonic and Tails, 01 = Sonic, 02 = Tails, and 03 = Knuckles. Tails and Knuckles may look strange if you select of one them to do Doomsday.