Instantly Unlock Metsu Mode
To instantly unlock Metsu Mode without making the 40,000-point milestone, go to the title screen and press on your arrow keys Up, Up, Up, Up, Right, Right, Down. A sound will confirm correct entry: in about five seconds, a cat will appear at the lower-right corner. Click it to enter Metsu mode. Note: This is not recommended for new players as it skips a large segment of the story.
Metsu Mode
Get 40,000 or more points in at least one puzzle game. At the title screen after the ending, click the cat in the lower-right for the new mode.
Special Text/Picture Files
If you meet the condition for Metsu mode, but ignore the cat and play again and get 100,000 points, the game directory on your PC has new files.