Sci-fi military RP on a ship is definitely what the Ryujo is, yup. And most of the Star Army (and as a consequence, the civilian population of Yamatai) is synths, although they're the bioroid kind. Aliens and androids are a good fit, since the Ryujo's crew is mostly non-standard races.
I see you marked 3 for all three ratings, which is definitely not normally my thing, although currently Ryujo still seems to have more blood, gore, and violence than almost any other plot ongoing at the moment, despite being at rating 2. And despite that they're currently fighting an enemy that refuses to fight with lethal force. I'm not sure if that's an incentive.