As an idea, the potential is immense. As a game, merely interesting.
It would be funny to play a game where the world would actually change progressively! Trees growing or being cut. Strutures being built , demolished or turning into ruins. Generated Mobs and generic NPCs, increasing or decreasing in number, changing location and status. Generated random events... Well, a virtually alive world... That's what Proteus is, in a smaller proportion.
Nevertheless, as it is, it still manages to be interesting for a couples of hours. Maybe more if you are in a explorers mood.
Proteus will deliver some entertainment in the form of fancy landscapes, dramatic scenarios, ambience changes, little surprises and will keep the curious gamer interested while the sense of wonder and discovery lasts.
My personal adivice? It's worth at least a try.