Before this update all the save files would had been saved locally and then synced with the steam cloud from time to time, but this didn't allways worked for everyone, some times the whole progress could be lost.
Anyway, I re-wrote the system to now save all you're savedata directly on the steam servers which should hopefully now make it nearly impossible to loose any progress ever again.
Nerdy Talk incomming!
In a nutshell, I reduced the amount of texture swaps and vertex buffers that have to be submitted to the gpu.