This had a decent start, and the riddles weren't too challenging. But by Day 3, it became almost unplayable for me because the attacks were too frequent and there was no prompt or explanation on how to get rid of the "ghosts" other than to "hit them on the head." I couldn't figure out how to get rid of them; clicking the screen did nothing, and neither did pressing any buttons. I eventually gave up after several tries. I don't think having something attack you as you're trying to answer riddles is a good idea. I honestly feel like it's just unnecessary frustration, especially if a player can't figure out what they're supposed to do to end it. I think it would have been better if the player was attacked every time they answered incorrectly, as being able to answer infinitely took any tension out of the riddle.
That being said, I liked the aesthetics of the game. I just wish there was a little more to it than just walking across a bridge.