What I made with the update so far..

• Completely Reworked the following Stages

  Knuckles' Angel Island
  Knuckles' Hidden Palace
  Knuckles' Hydrocity Zone
  Metal Sonic's Marble Zone
  Eggman's Angel Island, this stage in particular has been made extremely short, essentially just became an arena for the Oxiel encounter

• Completely Remade Knuckles' Special Stage from scratch

  Like you can see from the screenshot, this special stage has been removed and remade from scratch, now resembling the stage it was originally inspired by much more faithfully.
  
  With Special Coins I've talked about previously implemented in it, The special coins help when you mess up and touch the red spheres, taking away from the coins and restarting the stage. while dying in the special stage takes away from your lives.

• Minor adjustment to the following stages

  Tails' Green Hill
  Eggman's Launch Base