How could I feel the player engagement gap in my game?

In my game, you can build things, and research things to unlock new buildings. Besides a tutorial (I’m working on that right now) I have the problem of keeping the player engaged while the player waits to research new tech. I’m thinking of adding a colony system like in Surviving Mars, Animations to the buildings, and maybe vehicles transporting goods from building to building. I’m taking a lot from Factory building games and Surviving Mars.