If you bought the special edition with your current itch.io account you will still have access to the downloads to the paid version without having to pay twice. On the top of the A Dark Place page, it should mention that you own the game and it will give you access to the download link for that as well. If none of this is showing up, it may have been due to re-uploads of the special edition I did in which you can contact me through xer.workstation@gmail.com to receive a new updated download link for the paid version of the game. For your other question, the special edition features a debug menu which gives you the ability to update your save-file to access any of the major levels of the game at any time. This also gives access to hidden secrets, bonus content, and much more. You will also have access to free roam mode for any see how any level was designed using the ~ key. The special edition also features access to the entire in-game soundtrack which leads up to 70+ songs to listen to. Wallpapers are also featured in this version for personal taste and early access to the older version of the A Dark Place 2 Demo.