Developers of indie puzzle game Orgynizer have claimed that Unity said organisations like Planned Parenthood are "not valid charities" and are instead "political groups."

In a blog post, the EU-based developer LizardFactory said the plans to charge developers up to $0.20 per install if they reach certain thresholds would cost them "around 30% of the funds we have gathered and already sent to charity."

As Unity clarified the runtime fee will not apply to charity games, LizardFactory reached out to the company to clarify their game would be exempt from the plan.

However, Unity reportedly said their partners were not "valid charities" and were viewed as "political groups."

Profits made from the game go directly to non-profit organisation Planned Parenthood and C.S. Mott Children's Hospital, Michigan.

"We did this to raise money for a good cause, not to line the coffers of greedy scumbags," the developers wrote in a blog post. "We have been solid Unity fanboys for over ten years, but the trust is scattered all over the floor."

The developers are considering a move to open-source game engine Godot, "but we will have to recode our entire game because we refuse to give you a dime," they wrote. "This is a mafia-style shakedown, nothing more, nothing less."

Today, Unity responded to the ongoing backlash and apologised, acknowledging the "confusion and angst" surrounding the runtime fee policy.

The company has promised that changes to the policy will be shared in "a couple of days."