Costume Quest 2 had 5 exclusive costumes that were only available on some versions of the game. The Eyeball, Pumpkin, Robot, & Unicorn costumes were only available on Steam if you Pre-Ordered the game. The Sackboy costume was only available on the Playstation version. I believed the costumes were available in all versions of the game and was just locked away. Turns out I was right. After many many hours of a trying a bunch of things. I was finally able to Hex Edit the game and enable access to the exclusive costumes. It was a very simple change to make it work.

Some things to note. This change should work on saves you already have. If they don't then you will have to start a new game to get access to the exclusive costumes. Also once you do this mod. Your saves will only work on a modded version. If you try to load the save on an unmodded version of the game. The game will crash.

Note: I actually figured out how to do this 2 year ago in 2020. I had this guide posted elsewhere. But decided to share it here.

To access the exclusive costumes. You have to purchase them from Shady's Secret Shop.

If your having troubles following the instructions. I added a video to this guide that shows how to do the mod and shows the mod working. I did the mod on the Epic Games version to show that it also works on that version of the game as well.

( 1 ) Located the Costume Quest 2 executable.
On Steam it will be CostumeQuest2.exe & CostumeQuest2_DX9.exe.

( 2 ) Open the executable in a Hex Editor. I use Hex Workshop myself.

( 3 ) Use the Search function to locate the Text String 'Costume_Robot'.
Then zero out the following costumes --> Costume_Robot, Costume_Unicorn, Costume_Pumpkin, Costume_Eyeball, & Costume_Sackboy.
See the pictures below on how it should look Before and After the change.
In Hex Workshop, you do this by clicking on the left side and pressing '0' on the keyboard and you will see the text on the right change to a period/dot. So for example the first letter 'C' is '43' in Hex. '43' will be changed to '00'. You can just keep holding '0' on the keyboard until everything has been changed like in the picture.

( 4 ) Now save the changes.

( 5 ) After you save the changes you can close the Hex Editor, then go run the Game and you will see you have access to the exclusive costumes.

Before


After