My current novel is focusing on the character growth of the people involved while still being a scifi and action.
I can't say I have much experience working with science at all other than bullets go up, bullets come down.
a lot of the action and tactics used in my story comes from real-life experience in the army or second-hand knowledge of stories and learning points from the people that did experience it.
Character growth because I realise I'm a vastly different person that signed up compared to when I left.