This is a good start towards making a good puzzle game. I was stumped a few times, though not so stumped that I was raging. I think that many puzzle games are often too hard for casual gamers to complete, so having something more easier can be more fun.
I didn't really like the character designs (felt like it was too generic) or the voice acting. I would try to have the voice actors be more refined and emotional in their voices. I also didn't really care for the story. It's too generic and cliched. Perhaps some more specific details (such as describing the location more and having more interactions between the characters) would have helped.