I'm stuck at the point after defeating the Fire Demon. The game tells me to go to Akuma's Castle next, but I can't find it. Using the boat, I've found four new places on the world map -- two castle/city places (one on the grassland continent, one on the snow continent), neither of which I can enter (I can reach them and walk onto them, but that doesn't do anything), and two empty cottages on the other two continents, which don't seem to serve any purpose. Also, the world map is far too big -- exploring it is really tedious -- and the werewolves on the grassland continent are ridiculously overpowered, so it's easy to get stuck and have to hope for good luck to make it back to the boat.
Not a bad game up to this point though. I'm looking forward to trying out the sequel.