Clear Isolated Island.

Clear Botanic Base.

Clear Speed Slider.

Clear Amazing Arena.

Clear Marina Madness.

Clear Techno Tower.

Complete the game with bad ending.

Complete the game with good ending.

Collect 50 rings within any level.

Collect 100 rings within any level.

Collect 255 rings within any level.

Be onslaught by Metal Sonic.

Create sufficient debt to force a gameover.

Nothing is cooler than any sweet'n catchy music. Enter 00 00 00, 06 0B 11 and 00 08 17 on the first three rows of the Color Test and press Start. Visit the Sound Test for a special guest appearance.

Clear Isolated Island in Scenario in 2'30''00. (No level select.)

Clear Training 1 in 0'37''00. (No pause or Charmy.)

From standing in the bottom-left corner in Techno Tower, reach the top of the screen without using unique character abilities or Charmy. (Knuckles/Vector recommended, video in comment.)

Clear Training 2 in 1'00''00. (No pause or Charmy.)

Clear Training 3 in 0'37''00. (No pause.)

Clear Training 4 in 0'30''00. (No pause or Charmy.)

In the Bonus Stage, collect enough slow down power ups to hit maximum slowness.

In the Bonus Stage, collect enough speed up power ups to go really fast

In the Bonus Stage, collect the Combi Catcher Powerup. Pick a new partner between stages!

In the Bonus Stage, collect the Stage Select Powerup. Pick whichever Zone you like next time!

Gain at least 10000 points in a single Bonus Stage session by breaking the 500 point monitors. That's 20 monitors in case you hate math.

While controlling Charmy, collect the Shrink powerup.

As Mighty, beat the first phase of the final boss without touching the ground. No pausing allowed. Unlocks when phase 2 spawns in.

Collect the Grow powerup as Vector.

As Espio, beat the first phase of the final boss without touching the ground. No pausing allowed. Unlocks when phase 2 spawns in.

As Knuckles, beat the first 2 phases of the final boss without touching the floor. No pausing allowed. Unlocks when phase 3 spawns in.

Use the Swap powerup to take control of Heavy.

Use the Swap powerup to take control of Bomb.

Activate the Stage Select/Debug mode by going to the Color Test and entering the numbers 06, 0b, 11 in the 1st row, and 04, 00, 04 in the 2nd. Then Press start. This will pause most achievements.

Finish Botanic Base 1 with both players set to Heavy. No pausing allowed.

Defeat Metal Sonic and Metal Sonic Kai with Heavy and Bomb as Player and Combi respectively. No pausing allowed.

Start Botanic Base 1 with Player set as ********** and Combi set as Mighty. Holy Crackers, what a combo!