2D Boy has announced that its popular construction-based puzzle game World of Goo is one year old today.

In celebration of this fact, 2D Boy is offering gamers the chance to buy the game for whatever price they like.

"To celebrate the occasion, we thought we'd try a fun experiment - starting today and ending on October 19, you can buy World of Goo at whatever price you like - one cent, a million dollars, the usual twenty, or any creative number they let you type into the text field," announced 2D Boy. "If you played and liked the game but hadn't yet paid for it, this is your chance at redemption!"

That wasn't all 2D Boy had to announce. The developer also confirmed that World of Goo is heading to iPhone.

"We have it running well on the iPhone 3GS, and with a little luck we hope to get it running smoothly on the 3G as well. Hopefully more news on this soon," said the dev.