(Hedge)Hogging It All Up! - 50G (Original Achievement)
To get this Achievement, you must collect every collectible for the Collectible Room to the left in the white void.
You must collect: All Character Bios, All Movies, All Music, and All Artwork.
You will automatically get All Movies, and All Character Bios by completing the main story.
To get the Music and Artwork, you must clear every challenge gate (Rank doesn't matter) and collect every Red Star Ring in the game. Each ring will award either a Song or Piece of Artwork. and once you clear a challenge, jump up and hit the bell to make a music note appear. Grab the note to get the collectable. (Small Blue notes are Artwork, Giant Gold notes are Music)
Note: You must clear each challenge gate as Classic Sonic, and Modern Sonic.