Looks like the timer spotted on the Legend of Grimrock website was counting down to the announcement that preorders are underway for Legend of Grimrock 2. The dungeon-crawler sequel is due on October 15th, and word is those who make their commitment between now and then will get a 15% discount:

If you pre-order now, you get the game for a special -15% discount and both a Steam key and a standalone installer when the game is released on October 15th. Buying directly from us is the best way to support the developers!

You can also buy both Legend of Grimrock 1 and 2 for a special bundle price. Gain immediate access to Legend of Grimrock 1 and get the sequel on October 15th.