(Pocket-lint) - The Ouya gaming console launched on Tuesday at a number of retailers worldwide, immediately selling out at Amazon.com, Amazon.co.uk and Target, but many early backers on Kickstarter are still anxiously waiting for their consoles.

Ouya is an Android-powered console, and it's one of the most successful crowd funded projects of all time. The project raised over $8.5 million on Kickstarter. Despite the overwhelming initial success, Ouya has suffered many setbacks in recent months.

Read: Android-based Ouya console delayed until 25 June

It doesn't help that Ouya finally released weeks after its original 4 June launch date, but the company is more behind in terms of doling out consoles and Kickstarter rewards to early backers. So instead of receiving praise on launch day, Ouya's Kickstarter and Facebook pages are now brimming with complaints from early backers.

After reading that the Ouya sold out at several retailers, one commenter on Kickstarter wrote: "Normally I would say 'congrats', but in this case it is just sad to read. It just means that there are several people getting the Ouya faster and cheaper than the people that actually made this possible."

Read: Crikey, OUYA raises almost $8.6 million, that's $7.65 million more than needed

Ouya's Ken Stephens allegedly clarified to backers, according to a comment on Facebook, that a facility in Hong Kong recently shipped some consoles. Those consoles should arrive to early backers within two weeks. Over 63,000 people originally backed Ouya's Kickstarter project, although non-backers could also pre-order, so it's unclear how many backers are still in limbo.

Founder and CEO Julie Uhrman claimed in an email to backers on 8 June, according to Kotaku, that approximately 7,500 were still waiting. She also said Ouya was "working overtime" to fulfill its promises. 

"I am pissed," wrote Uhrman. "I did not promise to ship to most of you before we hit store shelves. I promised to ship to all of you."

Read: Kickstarter project OUYA brings free gaming to your TV

For those who did not give money on Kickstarter, the Ouya is still available for order through Best Buy, Ouya's website or other retailers in the US, the UK and Canada. It's also available to purchase in person at Best Buy, GameStop, Target or GAME.

Writing by Elyse Betters.