I have to say that Cold Cold Heart was actually better than Harley Quinn's Revenge. It felt like a darker version of one of the best episodes of Batman TAS(Heart Of Ice). Which it had many references and much faithfulness towards, even using more or less verbatim lines at several times, as well as plot elements and characters.
It was a lot fun to play and a good challenge. I still think the Mr Freeze fight in City was better than this one's, but the one here was pretty good as well. Another plus is that if you forget to accomplish any certain tasks before completing the story, you can finish thosw afterwards as the game allows you to free roam. Unlike Harley Quinn's Revenge.