Pass Act 1 of each stage with at least 50 rings
Complete at least 3 puzzles
First use the level select code and choose Debug. Highlight Muketi and change it to Yes.
Chaotic Space stage
Collect all 7 Emeralds before defeating Robotnik at ''Last Utopia'', and beat the "Last Utopia".
Unlock 6 Chaos Emeralds
First use the level select code, then go to the Debug screen. Highlight All Clear and change it to Yes.
Special Stage option
Construct all 6 puzzles.