There are 5 secret themes in the game currently. To access these secret themes you have to type Christmas, Confused, Cancer, Finnish, or Nicolas into your import under options.
Secret Pages Edit
In the bottom bar, there is a "donate page" button. When clicked, it sends you to https://ivark.github.io/about.html.
In this page, there is an "about me" text box, and a "super fun game" link that sends you to https://ivark.github.io/fungame/depression.html