With the acquisition of Slightly Mad Studios by Codemasters have probably also done the plans for the Mad Box, which wanted to bring the developer with ambitious plans on the market. Most recently, the project was having trouble keeping its investors anyway, and Codemasters may have even less interest in entering the hardware market.
The Mad Box was to become a high-end console targeting 4K gaming, 120fps and VR support. The goal was to create a simple development environment that is not bound by the restrictive guidelines of Sony and Microsoft. As exciting as the idea sounded, there were just as many doubts as the console hardware market is already saturated and sooner or later every new startup has been scrapped.
Although there is still no official statement on the current status of the Mad Box, as mentioned, the acquisition by Codemasters is likely to bury the further development, however. Officially, the studio is currently working on Project CARS 3, an unannounced Hollywood blockbuster, as well as a third, previously unknown project.
