I'm having a really hard time deciding on the age group for my novel. I know it's too long (106,000), and the characters are in college, so I know it shouldn't be classified as young adult. However, I think it's clean enough in terms of language and violence to be read by young adult readers, and I think it could be enjoyed by any age.
Also, the premise involves a parallel universe that is currently in the Vietnam War Era. So I think it's primarily science fiction, but also includes historical fiction, mystery, and romance.
I'm looking for tips on what age group to put it down as –– is adult or new adult a correct term for my book? Also do I market the book on multiple genres or just focus on science fiction? Any advice would be much appreciated.