Here's some photos of it:
Some specs:
There is 875 kg of cement.
It's about 2,1 * 2,6 meters in size (~5,5 m^2), which is fine for one player.
The slab is about 7 cm thick.
Total time spent on it was about 20 hours.
Total cost for materials was about 100 euros.
I have some instructions on how to do it on the photos, but if someone is interested in building their own, get in touch and I'll give more details.
Expect videos from a nice scenery.