|“||"CRITICAL SYSTEMS FAILURE! Repeat, CRITICAL SYSTEMS FAILURE! All attraction access is temporarily suspended. Please evacuate the park via the emergency exit ahead. THIS IS ALL YOUR FAULT!!!"||„|
|~ Dr. Eggman about the Terminal Velocity at Dr. Eggman's Incredible Interstellar Amusement Park.|
Sonic the Hedgehog has to travel down it to reach the space elevator to Earth. Eggman stops Sonic right at the elevator. Realizing what he must do, he pushes Tails into the elevator without him before the battle against the Nega-Wisp Armor]. After it was over, Eggman got sucked into a black hole by the energy created from the broken Mind Control Ray, as Sonic runs away from it and runs down to meet Tails back at Earth.
Act One (Wii)
Act 1 begins with Sonic racing down the huge space pathway as he is being chased by the Aero Chasers, a bunch of Motobugs and even a Giant Crabmeat robot. The act doesn't officially end, the screen instead just goes white.
The Nega-Wisp Armor serves as the final boss of Terminal Velocity. The stage starts as Sonic and Dr. Eggman are running down the space elevator turning to the left. Eggman first uses Purple Frenzy to put some distance between him and Sonic. He then attacks by using Laser, Spikes, or Cube to try to hit Sonic, having to suck up more Wisps to use the Color Powers. Sometimes, he moves behind you and not only will he use normal attacks, but he might use some combo attacks. Spikes and Cubes at the same time is one, and the other combo is Laser and Cubes at the same time. When he gets close, the player must use a Homing Attack on one of the arms, working up to the cockpit, where the player can use a Homing Attack twice to damage the Nega-Wisp Armor. The player can also boost for a third hit and some rings. After taking a few blows, the machine will hesitate to attack when the announcer proclaims a new ability where Sonic uses all the Wisps' abilities at once, called the Final Color Blaster. Sonic uses this attack to destroy the machine and send Eggman flying, as he explodes into a purple firework in the shape of his logo.
Act Two (Wii)
Act 2 is only 35 seconds long. It's just a straight shot down the rest of the pathway after Eggman is defeated. After Sonic beats Eggman, a black hole appears and engulfs Eggman, while following right behind Sonic. The only threat in the Act is the stage, crumbling underneath Sonic's feet, having him either have to Quick Step or jump to avoid falling. Nonetheless, Sonic fails to outrun the black hole, and passes out. The Wisps help him back to Earth.
In the DS version, it is simply an act involving Sonic running down in open space. Sonic will need to constantly gather energy for the Tension Guage to boost to move at high speeds because if Sonic slows down, the Nega-Wisp Armor's claws will approach behind Sonic and hit him. If Sonic runs into the walls, he'll take damage. After this phase, the player proceeds to battle the Nega-Wisp Armor.
- Terminal Velocity is the only stage where the boss comes before the second act, let alone any act.
- The term "terminal velocity" refers to the speed of a falling object when the drag force (friction) acting on the object exactly opposes the same magnitude of gravitational force on the object that acts on its motion. As such, the net (total force) acting on it is zero which means that the object cannot accelerate and hence the object will fall at a constant velocity.
- Terminal Velocity has no Goal Rings or Wisp Capsules besides White Wisps in Act One.
- Act Two is the shortest act in the entire game; only lasting 35 seconds.
- However Asteroid Coaster Act Three can be completed in about 5 seconds (with Super Sonic mode on).
- Act Two is also the only stage not to contain any rings or enemies.
- Terminal Velocity is the only stage where all Acts (excluding the boss battle) fade to white.
- Terminal Velocity, among other stages, is the shortest stage, only having two acts and a boss in the Wii version and one on the Nintendo DS version.
- The Nega-Wisp Armor is differently designed in Wii and Nintendo DS versions. On the Wii version, the Nega-Wisp Armor has a head and two arms. On the Nintendo DS version, it has a head and a tail.
- On the Terminal Velocity map there are white space-themed, sword wielding Egg Pawns that are supposedly the themed Egg Pawns for this stage. However, you never fight them in any of the acts, but by using moonjump in Act One & backtracking, you can use the Homing Attack on them.
- Although this level takes place on the space elevator anchoring the Tropical Resort to Earth, the design of the elevator is noticeably different in gameplay, than that of the cutscenes (most notably Sonic and Tails' flashback in the first cutscene of the game).
- Terminal Velocity bears a resemblance to the Final Rush stage in Sonic Adventure 2.
- While there are no PA announcements here (besides the level select PA announcement when the player selects it), in the cutscene after the Nega-Wisp Armor fight, a passing loudspeaker being sucked into the black hole says "At Eggman's Incredible Interstellar Amusement Park, you can feel comfortable knowing your safety is our number one priority.", to which Eggman ironically tells it to shut up before being sucked into the black hole.
- The black hole here does not seem to follow the laws of normal black holes, as the Wisps carried Sonic out of its event horizon and large pieces of debris were seen near where Eggman and his henchbots were in space. In actual black holes, anything sucked in gets crushed by hypergravity, and cannot escape once in the event horizon. Also, he could never have been rescued from it, since there is no time inside of a black hole.
- However this is likely because the black hole in the game was not formed naturally.
- This is the only world of the entire game which does not have 2D areas. This is also the only world in which Quick Step can be used permanently. Additionally, there are no checkpoints nor [Red Rings in any act.
- At the end of the boss battle, Eggman's pod explodes and has Eggman's emblem as a fireworks display. The player actually earns points for the pod exploding.
- The theme of Act One sounds similar in places to the Egg Dragoon boss theme in Sonic Unleashed.
- The black hole is the only thing that Sonic has not been able to outrun while being chased by it.
- There is a nod to Terminal Velocity in Galactic Parade on the video game Sonic & All-Stars Racing Transformed whilst on the third lap.