All the secret themes are unlocked by entering the phrases below into the "Import Save" option in the settings and pressing enter.

Also, using any of these for the first time will give you secret achievement 25.

• Phrase - Christmas
  Gives the game a Christmas-y theme.
  
  
• Phrase - Finnish
  Colors everything white and blue.
  
  
• Phrase - Confused
  Makes the game window sometimes become blurry, tilted, or have inverted colors.
  
  
• Phrase - Design
  Makes the game look like a 1990's website.
  
  
• Phrase - Nicolas
  Gives the game a brown tint and changes the background to a picture of Nicolas Cage.
  
  
• Phrase - Blob
  Blob emojis fall from above and the game's windows has a yellow tint.
  
  
• Phrase - Blind
  Removes all text.
  
  
• Phrase - Galactic/Stellar
  Adds animated stars in the background and gives it a blue tint. Both Galactic and Stellar have the same star effect, but Galactic has rounded button corners while Stellar has straight button corners.
  
  
• Phrase - Work
  Removes most of the game's flair, making the background and the buttons white, and changes the font to Arial.
  
  
• Phrase - Bliss
  Changes the background into the Windows XP background.
  
  
• Phrase - Aero
  Turns the game into the Windows 7 OS, complete with a taskbar and secret desktop icons that can be found by clicking the X on the top right. This theme even contains other games you can play within the game.