Indie developer 2D Boy has taken to its blog to discuss the design, promotion, release, and sales of gloopy iPad puzzler World of Goo.

The most interesting factoid was the game’s incredible success on iPad. Despite being a two year old game, and launching at the premium price of £5.99 / $9.99, World of Goo's best 31 day period on iPad dwarfed similar sale periods on Steam and WiiWare.

On WiiWare the team saw 68,000 copies sold in a single month, thanks in part to a mass mailing by Nintendo. On PC game distribution platform Steam, the studio took 97,000 sales in 31 days, due to two promotions at discounted prices. But on iPad, the developer cashed in 125,000 downloads, in a month.

That’s thanks, in part, to some rather shrewd methods on 2D Boy’s part. It worked closely with Apple to ensure World of Goo would be a featured title on iTunes, and even timed its release carefully so the game would be featured throughout 2010’s Christmas App Store lockdown. The developer also dropped the price.

Another interesting point is that the developer saw a handful of negative reviews regarding the game’s difficulty level - something it never heard about on PC or Wii.

“What we neglected to consider is that the iOS audience might be looking for a different kind of fast-fun entertainment, where punishment for failure, no matter how slight, is not an option, and no matter how badly you play the game you always feel you have a reasonable chance of success.”

To placate these people, an update added a more prominently featured 'skip level' button, and an unlimited number of skips.

“For exactly these cases of false expectations and disappointment, we wish Apple offered a mechanism by which a developer can issue a refund to unsatisfied customers.” The studio notes that it offers refunds to unhappy customers on PC, but can’t do so (easily) on iPhone. “We’d much rather have a happy non-customer than an unhappy customer.”

World of Goo is available now on iPad, for £2.99 / $4.99 / €3.99.

2D Boy