Pocket Size Games was founded in 2021 and operates as a "remote-first" studio between the UK, US, and Eastern Europe.
The team currently consists of 25 employees, including industry veterans from Disney and Electronic Arts.
Pocket Size Games advisors include former CEO and COO of 5518 Games Michael Casalino and Maxim Miheyenko.
With the investment, Pocket Size Games will develop its first mobile titles which are expected to be finished by March 2023.
The two projects currently under development are titled: An Epic Journey to Save the Planet, and Sense of Life.
The games will follow an "impactful" story about a world on the brink of ecological collapse.
"As soon as the Pocket Size Games team shared their visions for future game products, we understood that this was exactly the kind of thing we wanted to work with and something worth investing in," said Green Grey founder Dima Morozov.
Maxim Miheyenko added: "This is an excellent opportunity to create the next generation of story-driven games for our audience, which can help find themselves in the virtual world and solutions to real-world global problems that we are now facing."
Michael Casalino commented: "Life has changed for all of us in the last one and a half years, and now we crave new experiences that require the least amount of effort. We seek to develop the next generation of immersive, intuitive and realistic mobile games with compelling storylines and high-budget graphics that are also fully immersive and engaging."
In September, Green Grey invested $2.5 million in Infusion Games, with its first title, Cyber Wars, expected to be released in August 2022.