The US company behind video game sensation Fortnite said on Tuesday that it was valued at $28.7 billion in a round of funding from investors including PlayStation maker Sony.

Epic Games announced that it raised $1 billion, with $200 million of that coming from Sony. The Japan-based video game and consumer electronics giant first invested in Epic last year.

"We are excited to strengthen our collaboration to bring new entertainment experiences to people around the world," Sony Group chief Kenichiro Yoshida said in a release.

Plans for the funding included building social experiences into Epic's popular Fortnite and Rocket League games.

Hit video games such as Fortnite have seen use soar during the pandemic, and their creators see potential to expand beyond play to virtual parties, get-togethers or work-events.

"We are grateful to our new and existing investors who support our vision for Epic and the Metaverse," said Epic founder and chief Tim Sweeney.

The "metaverse", a term coined by sci-fi writer Neal Stephenson, refers to a shared online world in which users can hang out, spend money, consume media and potentially even work jobs.

Epic, which has recruited Brazilian football star Neymar and other celebrities promotion the game, said an estimated 350 million users.

The funding round comes as Epic prepares to face off in court with Apple in an effort to break the iPhone maker's tight grip on the App Store.

In legal filings, Epic has accused Apple of trapping people in its mobile device world and collecting "outsized commission" at the App Store that serves as the only source of digital content.

Apple counters that it has no monopoly when it comes to digital games and that the suit is part of an effort by Epic to portray "Apple as the 'bad guy' so that it can revive flagging interest in Fortnite".

Apple pulled Fortnite from its App Store in August of last year after Epic released an update that dodges revenue sharing with the iPhone maker, and the companies are now locked in a legal battle.

A trial in the case is set to begin May 3 in US federal court near San Francisco.