Since people asked for a way to pay for the game, this is essentially your way to make a donation.

I didn't want to just make an empty DLC, so I made a half hour long video where I talk about the process of making the game, show some videos of old builds, and look at some of my original concept art and puzzle designs. I'm also including some of those art files on their own, in case you want to skip sitting through half an hour of me enjoying the sound of my own voice (can't imagine why you wouldn't like that though).

To find the files after buying the DLC, select the game from your library and go to Properties->Local Files->Browse Local Files and extract the DLC zip file.

It's all pretty dumb and definitely not worth $5. I wanted to price it at $4.20 but Steam won't let me. I do not recommend buying this.