Game developer Valve has announced that the long awaited Portal 2, a combination between first person action game and puzzle title, has been delayed again, with the launch date moving to April 20 in North America and April 22 on the European market.

In the humorous tone that Valve updates related to new releases have been using for some time, the game developer stated, “This two month slip not only marks the shortest delay in Valve's proud tradition of delays, it represents the approaching convergence of Valve Time and Real Time. Though this convergence spells doom for humanity, it will not affect the new Portal 2 release date.”

Initially Valve talked about “the week of April 18” as the new window for the release but the company since then clarified the actual launch dates.

Before the new announcement Portal 2 was set to be delivered at some point during February, after Valve also pushed it back from late 2010 to early 2011, in a press release which said that actually developing video games is hard.

Valve is well known for the fact that they keep delaying their titles as long as needed to make sure that the experience delivered to players is the best one possible.

Lately only Left 4 Dead 2 appeared on the original set date, that of November 19, 2009.

Portal 2 is going to be a pretty different experience from the first game.

Gamers will still get to fire portals and use the laws of physics to their advantage as they progress through levels but this time around Valve is promising a much improved narrative while confirming the absence of cake.

The game will also include a cooperative game mode using two new robot characters.

Portal 2 is set to be released on the Xbox 360 from Microsoft, the PlayStation 3 from Sony, the PC and the Mac.