Roblox on Thursday received an enforceable undertaking following concerns about exploitation and abuse guardrails on its platform.
The eSafety Commission alleged the game was not meeting its obligations under the Online Safety Act's codes and standards.
Roblox does not have adequate measures to prevent contact between adults and under-16s, the office alleged. The company said it met its obligations.
The platform's service standard requires children's accounts to be set to private by default with accessible reporting procedures.
The scrutiny from the commission has the support of Communications Minister Anika Wells who said the gaming platform has "talked a big game" on child safety.
"Despite promises made to me in person and to the eSafety Commissioner in February, Roblox has not yet managed to clean up its act," Ms Wells told reporters.
"It is not good enough.
"Parents need to know that their children will not be approached by adults while playing the game."
Commissioner Julie Inman Grant said her department had been engaging with Roblox "for some time at senior levels".
"The company has responded, making a number of improvements to its service," she said.
"Their executives clearly understand that verifiable safety measures are critical to their long-term viability and success.
"We want to ensure that any platform with a high preponderance of kids to be a safe place where they can enjoy the benefits of online gaming, creativity and connection, including building their own worlds and experiences online."
Roy Morgan research estimates there are about 1.7 million Australian children on the platform.
Under the agreement, the platform committed to better prevent adults from contacting unknown children without parental consent and to ensure children's accounts are set to private by default.
Roblox also committed to implementing accessible report mechanisms notifying of complaint outcomes and agreed to engage a third-party auditor to assess its safety measures' efficacy.
All commitments must be enacted within three months.
It comes after the eSafety Commission tested the platform's guardrail claims earlier in 2026.
The testing found adults could send connection requests to children, and children's profiles were visible to others on the platform.
The platform launched restricted accounts for children and teens in June.
Roblox falls outside the government's under-16s social media ban as a gaming service.
The eSafety office also previously issued transparency notices to Roblox and other services about their basic obligations under Australian rules.
A report on the findings is expected later in 2026.