I suspect that there is a RaspberryPi in there somewhere, since the game itself is made to work on the RPi as well.
But the detailed specs for it is not shown on the website. Which is a bit stange, considering its listed at 899EUR and you would expect users to know what they are buying before committing to that amount of money.
If its a RPi, what version is included?
What software is it set up with and are there other arcade games available already set up?
What ports are available (eg. USB/LAN/SD card slot) are available without opening the casing?
The display specs?