After returning from Prison Island where he released Shadow, Eggman sets off to his secret base, taking notice that there’s an emerald sign on the area. Since Shadow had asked him to bring Chaos Emeralds the next time they meet, Eggman takes off and finds Knuckles and Rouge fighting over the Master Emerald, which is not a Chaos Emerald like he initially thought. Still, he snags it, thinking he could use it for something, but Knuckles foils his plans by smashing the emerald into pieces. Eggman leaves the scene baffled at the echidna’s antics and continues his way back to his base.
Sand Ocean is desert themed, with an interesting concept of bottomless pit, since the level is constructed above quick sand where the Egg Walker will sink into immediately if in contact. It is Egyptian themed as well with large murals, hieroglyphs in small square platforms, and giant statues with an Eggman-like head on top. For some strange reason, there are flags and gas tanks with the G.U.N.'s logo marked on it.
The major gimmicks of this level are the pillars that can be knocked over by locking-on to the dynamite packs attacked to the base of it, forming new paths and access other platforms and gyrator platforms that make alternative paths easier to access.
Collect 100 Rings
If the player picks up every Ring along the main path and shoot the Floating Item Boxes along the way, it is possible to collect 100 Rings in under two minutes.
Find the Lost Chao
Jump onto the small platform from the rotating one that otherwise leads to the second Point Marker. Being careful not to hit the Spring. From there, wait for the moving platform ahead to come, then jump onto it. While riding the platform, the player should see two more platforms on the left: the closest one has fences on two sides, and the other is stacked with four Iron Containers. As the player moves toward the closest platform, jump and move around the fences. From there, blast the four Iron Containers before hovering over to the other platform. Hover once more onto the bridge ahead, and walk toward the altar where the lost Chao is waiting.
Reach the Goal within 4:00
If the player gets the Jet Engine in Lost Colony, the player will not have to wait around for of the moving platforms in this stage. It is best to have that Level Up Item equipped before playing this mission.
Clear Hard Mode
Aside from the usual addition of more enemies with increased aggression, the only other major change here is the disappearance of some of the moving platforms. If the player practices their hovering skills, this mission will be easy.
Big the Cat sighting
Step close to the Goal Ring, and rotate the camera to the left to see Big sitting on a platform out in the sea of sand.
Chao Container locations
Before crossing the third pillar that needs to be knocked down, walk past it to see a pair of swinging Spiked Balls. The first Chao Container can be found behind them.
After the first Point Marker, a rotating platform, and a series of moving platforms, the player will arrive at a platform with some Dynamite on it. There, the second Chao Container can be found.
After the second Point Marker, the third Chao Container can be found atop a tall platform.
The upgrade in this stage is the Mystic Melody for Dr. Eggman. It can be reached by choosing the left platform on the first gyrator. The player must be careful of the bombs which a Bomb Beetle throws and he/she must either dodge them or shoot at the Bomb Beetle.
Differences between the Dreamcast and the GameCube version
Some robots were positioned differently from the Dreamcast version in this stage.
The ceramic jars were added in the room with the circle of rings on the floor in the GameCube version.
Just before the last Point Marker, the player will need to lock-on and destroy two water containers blocking the way in the Dreamcast version. This was changed to three water containers in the GameCube version.
In mission 3, the player is not required to use the Mystic Melody in order to obtain the Chao.
The quicksand in this level gives the player slightly an extra time before they lose a life (much like in Egg Golem's boss battle). In other words, if there is a close Spring near the player while they are sinking in the quicksand, the player can slightly move toward it while sinking. And when the stage's time stops, they should immediately use the Spring before it is over. This glitch allows for navigating the stage with a big time bonus, as the time counter has stopped recording.