I will start with the problems. I played on my low performance asus laptop. It's take a long time to load the game and it's stuck sometimes on 42% or 70%+ on my Firefox, after the page reload, the game proceed the loading. On Chrome it's much better, but sometimes I find some problems that I had to reload. Once after first fall, the player stuck in the crouch position. Ok, maybe most of these problems causes by the low performance, but I guess you will prepare it to mobile.... So you must to optimize it, or use other engine IMO
Now about the game. First of all it's short (once you figure out the way, and find the place). Second the game is awesome. Really it's very atmospheric, beautiful and deep journey. The ending is beautiful too, it took me a long time to figure out the way, but it's worth it.
P.S sorry for my Eng