Back in the late '90s, Sonic Team, together with Traveller's Tales, released Sonic 3D Blast for the Sega Saturn.
The game was a port of the earlier Sonic game (of the same name) released for the Sega Mega Drive / Genesis and featured higher-resolution textures, weather effects, and new 3D-style bonus stages, to take advantage of the more sophisticated 32-bit hardware. While not the most highly-regarded of classic Sonic games today, it certainly has its fans within the Sonic community, especially among those who grew up with the title back when it was first released.
If you're wondering why we're telling you this now, well it's all a bit of a long-winded preamble in order to introduce you to a few interesting discoveries that happened recently within the game's community. Over on Twitter this past week, Bo Bayles (better known as Low Context Burning Rangers) recently stumbled across a few cool hacks that can be performed in the game, documenting them inside of a thread.
These include the ability to change Sonic's scale to make him larger or smaller, the potential to unlock a previously undocumented debug camera mode, and the introduction of semi-playable versions of Knuckles and Tails into the Sega Saturn's bonus stages. Why semi-playable? Well, it seems that if you perform any missing animations as Tails then the game will crash.
According to Bayles, he doesn't believe this discovery means Knuckles or Tails were ever meant to be playable in the game, but that the swap simply exists because the models can be switched over. As for the Sonic scaling, he speculates that is a feature left over from Nights Into Dreams (another game from Sonic Team) where the enemies Crewle and Pole could produce a special orb in order to shrink the main character.
If you find this at all interesting, we recommend checking out Bayles' Twitter for more finds like this.