When Sega created Sonic the Hedgehog they were in a unique position. Their Genesis console was leading the console wars. With their Master System console, Sega were in a distant second place against the Nintendo Entertainment System. With the Sega Genesis the competition was NEC who were quite inept at how North American gamers played.
While Sega were to limp out of the 16-bit era with a too close to call the winner run against Nintendo, 32-bit was different. Sony basically handed Sega and Nintendo their lunches. One reason Sony were able to do this was the success of Crash Bandicoot (Sony PlayStation exclusive during the 16-bit era).
Crash Bandicoot was a 3D, sometimes 2.5D sidescrolling, action platform title. Crash Bandicoot 2 expanded on the 2.5D sidescrolling levels a bit. This is the basis of this hack.
Someone modded Crash Bandicoot 2 to include Sonic the Hedgehog instead of Crash. What is funny here is, it works. Quite well.
We see Sonic run through what is apparently level 2 of this game. The levels feature the Crash Bandicoot graphics with minor changes. Crates offer rings, green TNT crates are still dangerous, and Dr. Robotnik/Eggman is waiting for you.
Being 2.5D, you can expect to travel into the background for some sections. This usually means grabbing rings from crates. This idea is also used to transition between levels as well. Too bad as this could have been used in so many more ways – avoiding enemies or projectiles.
If you are not familiar with Airumu, I do not blame you, I had no clue who they were till this article. They are a prolific game modder, and clearly a fan of Crash Bandicoot.
If you do not believe me, check out their YouTube channel. Tons of mods, with most featuring Sony’s former mascot-ish character.
Airumu has done many mods and their work is worth checking out.