Sky Chase (スカイチェイス Sukaicheisu?) is a sub-game stage from Sonic Adventure. Sky Chase is played while Sonic and Tails chase Dr. Eggman's Egg Carrier in the Tornado (and, later, the Tornado II). The point of Sky Chase is to survive the onslaught of enemies and gain as many points as possible. Sky Chase is named after the Sky Chase Zone from Sonic the Hedgehog 2, which also involved Sonic and Tails in the Tornado, fending off Badniks.
After Dr. Eggman stole two Chaos Emeralds from Sonic and Tails after they fought Knuckles, he used the Emeralds on Chaos who became Chaos 4. After Chaos was defeated, Eggman escapes to the Egg Carrier and Sonic and Tails give chase in the Tornado.
After getting to the front of the Egg Carrier, a huge cannon comes out and fires a shot, tearing a wing off the Tornado, Sonic and Tails are separated and Tails makes the Tornado II.
After Sonic finishes the Red Mountain stage, he sees Tails in the new Tornado and they give chase again. Sky Chase II is much like the first, but with greater difficulty and a darker backdrop. When Sonic and Tails reach the back, Tails reveals that the Tornado II can transform into attack mode. The Tornado II is faster and stronger which the two use to disable the cannon and land on the Egg Carrier, unfortunately, Tails forgot that the Tornado II has no landing gear in that mode and they crash.
- Both Sky Chase and its second act are both modeled after another of Sega's video game series, Panzer Dragoon. Although the controls are simplified in comparison, the basic control scheme between the two games is the same.
- Sky Chase is one of two stages in Sonic Adventure and Sonic Adventure DX: Director's Cut to be named after past zones in the Sonic franchise, the other one being Ice Cap.
- Sky Chase is named after the Sky Chase Zone from Sonic The Hedgehog 2, sharing more than just the title. It employs the same idea of fighting flying enemies and chasing an aircraft made by Dr. Eggman.
- This Sub Game is accessible to Sonic and Tails only.
- Originally, there was going to be a mechanical dragon miniboss in Sky Chase, but was scrapped because of difficulty and time restraints. This is shown if 'E' (center camera) is held during the level.
- Through hacking, when he is loaded into the game, he is revealed to only have his flying animation completed, he does not have any attacks. He simply just flies behind the Tornado and does nothing else, meaning he was scrapped very early in production. It is unknown what he eventually would have done since he is incomplete, although it is possible that at one time he could have been the reason why the Tornado was shot out of the sky.
- In Sonic the Hedgehog 2, the player can control Sonic or Tails (depending on who they pick) and the other will fly the Tornado, but in Sonic Adventure and Sonic Adventure DX: Director's Cut it doesn't matter who you select; Tails will always fly the two planes and Sonic will stand on them.
- In the Japanese audio of the game, Sonic and Tails will scream in a panic as the Tornado spirals out of control. In the English audio however, they respond with excitement.
- During the production of the Dreamcast version, Sonic R/Sonic Jam models were used in this stage as placeholders. This is seen in pre-release screenshots of the game. In the final version, the models are still noticeably lower-poly than the usual ones and look only slightly modified from the Saturn ones (to include green eyes for Sonic). The DX version uses the same higher-poly models as the rest of the game during Sky Chase.