Very original and innovative idea, and I loved how it gradually became clear what you needed to do without any specific instructions. I liked the exploration aspect and the extra details here and there which gave the environment more flavor. Getting the last thorn and reaching the forge were pretty frustrating though. Maybe you could add more audio feedback to make up for the lack of tactile information.
I'm not sure I understood the point of the QR codes as opposed to just having text in the game world. I ended up using Firefox's screenshot functionality along with the zbarimg command-line tool to decode the text, which felt like an unnecessary hassle.