The Potato Sack sale kicked off over the weekend on Steam. The sale knocks 50% off 13 indie games, including Super Meat Boy, Amnesia: The Dark Descent, Killing Floor and more. The whole bundle is 75% off, and you'll get a potato hat in Team Fortress 2.

This isn't just an ordinary sale, thought. There's something weird and potato related happening. Several games in the potato pack have received some unusual updates. Egyptian hieroglyphics have been found in Amnesia, potato references have been found in Defence Grid: The Awakening, and plugging a Razer peripheral in to Kick It! will trigger one of fifteen potato related phrases like this one "never trust a potato...they have eyes everywhere. They are always listening...we never went to space! SPUDnik was a Russet Conspiracy!" What the spud is going on?

VG247 note that a wiki has been set up to collect the mounting clues, though nobody has any idea where any of it is leading. Valve revealed Portal 2 through a series of encoded images and radio messages patched into Portal 1. Could there be another reveal on the cards, or is it all an elaborate, long running April fools hoax?

Here's a list of the games that are part of the potato sack sale. Head over to Steam to take advantage of the deals. There's no end date for the sale yet.

1... 2... 3... KICK IT!
AaAaAA!!! - A Reckless Disregard for Gravity
Amnesia: The Dark Descent
AudioSurf
BIT.TRIP BEAT
Cogs
Defense Grid: The Awakening
Killing Floor
RUSH
Super Meat Boy
The Ball
The Wonderful End of the World
Toki Tori