My first stab in making variation puzzles. After talking to Tom Collyer, I have decided that I currently do not possess the skills to make a puzzle that is both aesthetically pleasing and logically interesting at the same time, so I will generally go for one or the other in future puzzles. Seeing that this puzzle is not particularly beautiful looking, you can imagine that it is quite hard, and that would be a reasonable guess. One trouble with making variations such as this is that you are always uncertain whether you missed a black circle somewhere.
Standard Masyu Rules. Additionally, all possible black circles are placed in the puzzle. ie. If the path goes through a square without a black circle, then it must either go straight on that square, or turn in one of the squares adjacent to it.