Dragon Princess is a great game with a cute artstyle and fun, satisfying gameplay. The dungeons and objectives have a good variety which helps keep the player engaged throughout the game, along with the persistent upgrade system and the many companions.
My only complaint however, is that the game is a little too easy. I think having a set range for projectiles would help in that area - in each level I would fight some enemies, move along a little bit in a certain direction and find a veritable hoard of gold coins and mostly dead enemies.
Another thing that could be added are difficulty modifiers (such as more enemies, more enemy health, etc)