Sonic 1 Special Version is Sonic the Hedgehog hack made by EditChris.This hack add new level layouts, New Art, A lot of ASM changes/add, MegaPCM driver improved and a lot of music added.

Sonic 1: The Special Stages is a hack of Sonic 1 by SonicVaan. This hack removes standard Sonic gameplay and replaces it with the Special Stages which normally were only accessible by the Giant Rings at the end of each stage.The actual special stage layouts have been touched for every stage.This hack is actually on hold. Future releases are not to be expected.

Sonic the Hedgehog Spinball, or Sonic Spinball (ソニック・スピンボール Sonikku Supinbōru?), is a pinball video game in the Sonic the Hedgehog series. It was originally released for the Sega Mega Drive/Genesis in 1993 and later ported to the Sega Game Gear and Sega Master System in 1995.The term "Spinball" is a portmanteau on pinball and "spin dash", a move Sonic performs. It, along with Dr. Robotnik's Mean Bean Machine were the only two Sonic games released to use characters and elements from the Adventures of Sonic the Hedgehog and Sonic the Hedgehog cartoons.

Space Harrier (スペースハリアー Supēsu Hariā?) is a third-person rail shooter game, released by Sega in 1985. It was produced by Yu Suzuki, responsible for many popular Sega games. It spawned several sequels: Space Harrier 3-D (1988), Space Harrier II (1988), and the spin-off Planet Harriers (2000). Space Harrier was originally made for the arcades, and later saw ports to many home game systems. Space Harrier's release on the Sega Master System is notable, as there were two versions: one was just like the arcade, while the other, entitled Space Harrier 3-D was actually a sequel. It was one of the first arcade games to use 16-bit graphics and Sega's "Super Scaler" technology that allowed pseudo-3D sprite-scaling at high frame rates,[2] with the ability to scale as many as 32,000 sprites and fill a moving landscape with them,[3] along with over 32,000 colours displayed simultaneously on the screen. It also introduced a true analog flight stick for movement, with the ability to register movement in any direction as well as measure the degree of push, which could move the player character at different speeds depending on how far the stick is pushed in a certain direction.[4] The game was also an early example of a third-person shooter;[5] it was influenced by the earlier 1982 Sega game Buck Rogers: Planet of Zoom, and Space Harrier in turn influenced later 3D shooters such as Nintendo's Star Fox/Starwing in 1993.