I killed the first Reincarny, then went back to the shop to give the dead drunk's bone to the dog so I could get the string. When I clicked on the ball of string, the game froze. The only difference between this time through and when I succeeded at getting the string is that I hadn't killed the first Reincarny yet. So it looks like you can't go back to get the string if you kill him first. I would have reviewed with a 10, but a game crashing bug is a -2.
Also the tenth medal isn't in the public medal list.
Aside from that, the game was fine and the puzzles were about the right level of difficulty. I didn't know you could go another screen left from the soul pinata screen though, so you may want to think about moving that arrow or changing its shading or something to make it a little more obvious; had to go to the walkthrough to find out about the screen there.