History WhatCouldHaveBeen / SonicAdventure

* Going by concept art, Hidden Palace was originally going to be in the game, seemingly accessible through a secret entrance at the feet of a huge echidna statue. Interestingly, the Emerald Altar there was depicted as being within a large pillar structure [[ContinuityNod per the Japanese manuals]] of ''Sonic 3'' and ''VideoGame/KnucklesChaotix'', and still contained the Master and Chaos Emeralds, implying they had remained there since being returned in ''VideoGame/Sonic3AndKnuckles''. In the final game, the Chaos Emeralds are scattered all over the land, and the Master Emerald was relocated to an outdoor altar. Interestingly, when the concept art was revealed on social media, it was attributed to Lost World. If this is accurate, then it would imply that Hidden Palace was reworked into Lost World at some point (likely when it was decided to implement the outdoor altar), explaining similarities between the two areas such as presence of the legendary dragon/Perfect Chaos mural (implied by the Japanese Sonic 3 manual to be in Hidden Palace).

* In 2020, Satoshi Okano, a former ''Sonic Jam'' artist and field artist for ''Adventure'', revealed on Twitter that [[https://pbs.twimg.com/media/Ee-1yn5WAAYu6q1?format=png&name=small the bikini-wearing character seen in posters of Speed Highway]] was [[https://twitter.com/okanotion/status/1292455545853448192?s=20 a planned character who ultimately went unused]]. Three years later, he revealed [[https://twitter.com/okanotion/status/1727610208363667752 two full-body concept sketches of "Spider-Girl,"]] along with a character known as "Fly the Vampire," and would have possibly been the spider's rival or enemy. These two concepts would possibly later be combined to become Rouge the Bat (based on Spider-Girl's heart motif and the Vampire becoming just a normal bat).

[[caption-width-right:300:Screenshots of early concepts of the [[UsefulNotes/SegaSaturn Saturn]] version of the game]]

* The game was planned to have [[https://www.sonicstadium.org/2014/03/cancelled-sonic-adventure-burger-king-promotion-comes-to-light/ a kids meal tie-in from Burger King]] featuring ten different toys, set for a release on December 10, 1998. Most likely due to Sonic Team delaying the American version of the game to patch up the glitches in the original Japanese version, this promotion was scrapped.

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/800px_sa1_ss_prerendered_concept_art_2.png]]
[[caption-width-right:350:One can only imagine how this game would’ve been on the Saturn.]]

* Going by concept art, Hidden Palace was originally going to be in the game, seemingly accessible through a secret entrance at the feet of a huge echidna statue. Interestingly, the Emerald Altar there was depicted as being within a large pillar structure [[ContinuityNod per the Japanese manuals]] of ''Sonic 3'' and ''VideoGame/KnucklesChaotix'', and still contained the Master and Chaos Emeralds, implying they had remained there since being returned in ''VideoGame/Sonic3AndKnuckles''. In the final game, the Chaos Emeralds are scattered all over the land, and the Master Emerald was relocated to an outdoor altar.

* According to some DummiedOut voice clips from Tikal, Super Sonic was going to be playable in the same manner as the Genesis games (collecting 50 rings will let you transform during a level) The idea was scrapped due to the games level design not being able to adapt to Super Sonic's speed and controls. Although it's possible that Metal Sonic skin uses the unused code for it.

* A very early Dreamcast prototype, called the "[=AutoDemo=]", has been unearthed and searched through. 3 test maps and many early maps were found, but the biggest find was the map geometry of the early Windy Valley, as seen in the game's earliest promotional materials and in the intro cutscene. The map, along with structures in the test maps, suggested that the game would have been more dependent on Sonic's momentum, rather than his raw speed, and may have featured physics similar to the Genesis games. Other differences is the level being much more vibrant, with a lesser emphasis on realism, and having a significantly more expansive layout that had many more alternate paths and took longer to clear. This might explain why the final level's Mission A clear time is so forgiving, having been adjusted for the original incarnation. WordOfGod is that the original Windy Valley was scrapped because it needed a lot of polish (likely due to the final physics system being unsuitable for it), but time constraints forced them to make a new, simplified version from scratch.

* A screen of the original incarnation of Windy Valley was used to promote ''Sonic Adventure DX'', implying that this one was originally going to bring back scrapped content intended for the original Dreamcast version. This might explain the extraneous ''Director's Cut'' subtitle.

* A very early Dreamcast prototype, called the "[=AutoDemo=]", has been unearthed and searched through. 3 test maps and many early maps were found, but the biggest find was the map geometry of the early Windy Hill, as seen in the game's earliest promotional materials and in the intro cutscene. The map, along with structures in the test maps, suggested that the game would have been more dependent on Sonic's momentum, rather than his raw speed, and may have featured physics similar to the Genesis games.

* Hidden Palace was originally going to be in the game, seemingly accessible through a secret entrance at the feet of huge echidna statue. Interestingly, the Emerald Shrine inside still contained the Master Emerald and even the Chaos Emeralds, implying they had remained there since being returned in ''VideoGame/Sonic3AndKnuckles''. In the final game, the Chaos Emeralds are scattered all over the land, and the Master Emerald was relocated to an outdoor shrine.

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/sonic_adventure_sega_saturn_era.png]]
[[caption-width-right:350:One can only imagine how this game would’ve been on the Saturn.]]

* Hidden Palace was originally going to be in the game, seemingly accessible through a secret entrance at the feet of huge echidna statue. Interestingly, the Emerald Shrine inside still contained the Master Emerald and even the Chaos Emeralds, implying they had remained there since being returned in ''Sonic3AndKnuckles''. In the final game, the Chaos Emeralds are scattered all over the land, and the Master Emerald was relocated to an outdoor shrine.

* Shortly after Creator/SonicTeam decided to redesign Sonic, there was a competition held between some of Sonic Team's artists on how Sonic should be redesigned, the top 4 submissions for Sonic's redesign, showing different designs of him, were showcased in the Japanese magazine, Sega Harmony, which can be seen [[http://archive.is/ui0O3 here.]][[note]]From R - L, top to bottom:, Yuji Uekawa, Satoshi Okano, Naoto Ohshima, Takumi Miyake.[[/note]] Yuji Uekawa's design ultimately won and would become the basis for Sonic's Modern redesign.

!!Examples!!

[[caption-width-right:350:One can only imagine how this game would’ve been in the Saturn.]]

** It also shows that Chaos originally had cat-like pupils in his eyes.

* As stated above, ''Sonic Adventure'' was originally in development for the Sega Saturn, with the Sonic World featured in ''VideoGame/SonicJam'' serving as a prototype. As such, there are some elements from ''Jam'' that can be found in ''Adventure'' such as [[https://www.youtube.com/watch?v=wtSAIyXJUdE some of Sonic's animations]] and an unused spring that can be found via hacking.

[[caption-width-right:350:These are screen mockups from the Sega Saturn stage of development.]]

The game went through a lot of changes especially going from one console to another.