Well, yesterday, I went back and added a good chunk to an older chapter. Pushed the total word count to about 70,800. Maybe my trusted editors will give me ideas to expand it but I'm pretty happy with that word count, for the moment.
At the very most, I could see pushing it to 80,000. After that, it'd be just useless padding. With an action/character driven story like this, that would just muddle down its fast pace.
To answer your question, though, Tin: I'm honestly not sure. It's a hard-boiled detective type story, but in a superhero setting. I guess sci-fi...ish? It's hard to say. I was heavily inspired by Simon R. Green's Nightside series, which is fantasy detective, along with John Zakour's sci-fi detective series. Both series are relatively short, certainly in comparison to the ridiculously thick fantasy or sci-fi books on the shelf. I think mine falls into about the same word count or maybe a little lower.