~Screenshot from the scrapped Sonic-16 (not official title). The game was cancelled by Yuji Naka because of its slow-running demo, but was meant to tie in to the Sonic the Hedgehog TV series, being more story-driven than its predecessors. One developer of Sonic X-Treme claims that Sonic-16 was another of the former’s developmental stages~
~EDGE Magazine’s “The Making of Sonic X-Treme”, which also includes the story of its cancellation~
(Source: info.sonicretro.org)
In the scrapped Sonic Mars, the end of each level was to be celebrated with a cutscene between Sonic and the character he finds in that level. His celebration with Knuckles involved the two spin-dashing each other until fireworks erupted around them.
(Source: info.sonicretro.org)
~One of many Metal Sonic designs from the scrapped Sonic X-Treme, this boss fight was the furthest along in terms of development~
In the scrapped Sonic Mars, it was planned that Sonic would rescue each character, and Sonic and the rescued character would have an end-of-zone animation together. When Sonic rescues Antoine, Antoine apparently tries to high-five him, but trips.
