Heat Factor: Explicit M/M action. Where one of the characters is an alien with erogenous prehensile hair. I would call it hentai adjacent. (Mom, please do NOT Google hentai.) (Note: After writing this, I Googled hentai, and according to Wikipedia, I am using the term incorrectly. What I mean is: Tentacles.)
Character Chemistry: Sudden.
Plot: Alien and Space Station Detective bone and also solve a mystery.
Overall: Started charming, ended preachy.