Recent reviews by Valtos

Highly addictive, yet you can quickly reach a point, where you have nothing new to do.

I have already lost my achieved progress, twice. Sure this game is worth every penny, but its really frustrating starting over again. Perhaps its not developers mistake, but steam cloud is actually terrible. You have no assurance, that it will keep the last uploads.
Just keep your saves somewhere safe, and you are always good to go.