Encountering the dragon without having a Divine Blade means you're dead, which is just poor game design seeing as how the shops are random. Other than that the game is ok.
Haha, I actually beat the game before I even found out you could upgrade stuff. Some added difficulty would be very much appreciated. Also why does the acid have a radiation symbol? Radioactive acid maybe? :P
Certain bosses are impossible to beat with certain character builds, and since you can't change character build or train more before the boss, this utterly ends the game. Pretty bad design there...
It would be more fun if you had more space to input commands. That way, in stead of there being only one right solution and failing otherwise, you could succeed more easily and the challenge becomes finding the shortest solution in stead of finding the one solution that works. It would allow for 'sub-optimal' successes for an easy solution and 'perfect' successes for the challenge.