The TGS menus from the Dreamcast version are still present, to access it, replace the seven bytes at C53A in sonic.exe with seven 90 bytes, or install the 'TGS Menus' mod from this page.
The Collision Debugger from the Dreamcast version is also present, but it has been almost completely removed.
This also enables Free Movement mode for every character, except Tails, moving around for a bit will also activate a display. Setting 0x3B29D08 to 1 in Cheat Engine will enable a Debug Movement display showing all invisible walls and inactive objects on the map. File: SADXPC Leftovers.rar (280 KB) ( info)