A number of well-known indie games have been adding playable and decorative content themed around next week's release of
Portal 2 as part of a promotional alternate-reality game surrounding the title.
The thirteen indie games included in Steam's discounted
Potato Sack collection have seen a number of free downloadable updates this month, offering everything from hidden messages and password-locked "login pages" to entirely new
Portal-themed levels.
Five new levels were discovered in the PC version of
Super Meat Boy today, for instance, while an
Audiosurf update allows players to control a floating
Portal gun instead of the usual surfboard.
Updates to The Ball reportedly add an hour of new content through levels featuring
Portal turrets.
Other additions include new levels and achievements in zombie shooter
Killing Floor, a new "Test" level in experimental rhythm game
Bit.Trip.Beat, and changes to dozens of maps in
AaAaaAaAAA!!! -- A Reckless Disregard for Gravity.
Purchasing The Potato Sack on Steam also grants access to a new "potato hat" item in
Team Fortress 2 and exclusive co-operative bot skins in
Portal 2.
The PotatoFoolsDay ARG, as
followers have come to call it, presents a seemingly unprecedented coordination between a large number of indie game makers, providing cross-promotional opportunities for the developers involved as well as new gameplay opportunities for players.
Similar cross-marketing content has appeared in indie titles in the past, with Team Meat's
Super Meat Boy included 15 unlockable characters from other indie games, while three Xbox Live Arcade titles released last year
included cross-promotional content for users that purchased multiple titles.
