Spring Yard Zone

Spring Yard Zone is a location in Sonic.exe: The Spirits of Hell and is the final level of the Knuckles & Robotnik Duo Ending.

Appearance
Spring Yard Zoen is a city underneath a purple sky filled with pinball-esque springs, bumpers and flippers. Dark purple mountains and green vegetation as well as several buildings are visible in the distance.

Story
After Dr. Robotnik convinces Knuckles to take them to the Zone as they can work together to get a Chaos Emerald, they teleport to the Zone using the Master Emerald. Knuckles tells Robotnik to stay with him as Exeller could be there, but Robotnik laughs maniacally and reveals that he tricked him again. He flies off with his jetpack to get the Emerald for himself as Knuckles angrily yells that he will get him.

Robotnik eventually reaches a dead end, where Exeller corners him. He calls him an idiot for backstabbing Knuckles and is about to kill him when Knuckles knocks him down with a Spin Dash. Robotnik apologises to Knuckles, who promises to defeat him once Exeller is gone. He uses another Spin Dash, but Tails.exe blocks it. Robotnik is horrified, asking Exeller what he did to Tails, before Exeller replies that he lost his "game". The player must then defeat Tails.exe as Robotnik and Exeller as Knuckles. Once both bosses are defeated, the player must play through a short platforming section as Knuckles to reach Robotnik and escape to Mountain Peak.

If Robotnik is killed but Knuckles wasn't,

If Knuckles is killed but Robotnik wasn't,

Bosses

 * Tails.exe: The player controls Robotnik. The arena is a platform over the Zone with 6 platforms over it, each with an orange energy ball on it. Tails will fly towards Robotnik and will kill him on contact, so Robotnik must trick him into flying all of the energy balls. This will trap Tails in a force field and allow Robotnik to escape.
 * Exeller: The player controls Knuckles. Knuckles starts with 1 ring, and there are 4 more at the bottom of the arena. Exeller attacks by shooting energy balls at Knuckles, and then the player must get him to shoot one of the golden bumpers on the walls to deflect it back at him. However, Exeller will send a clone at Knuckles to make it harder. Once Exeller has been hit 4 times, he will seemingly die, but it turns out Knuckles only killed a clone of Exeller.