I enjoyed playing this. It fits the profile of an nice casual fun flash game. I will have to agree with weezl that the crafting system is more of gimmick then anything else, you might as well just get a random drop at the end of the battle. It would be nice if there was something more to it.
I played only for about 5 levels i think cause i am kinda in rush now, but it looked like the bosses are repeating itself too much, even at level 5 it was the same guy with maybe slightly more health, if anything he could be accompanied by something special to that boss, like it could be a ninja boss with 4 ninjas around him? Maybe you have that and I just didn't get there though...
Also i find the voice acting a little bit annoying after a while. Its fine and all but theres too much of it to every small single event and that makes it kinda overused.
but overall i liked it
and I had to force my self to stop playing it cause I don't have the time right now :d