It is already noticeable that this game has some plot branches, but there are still very few of them: the plot is still generally linear.
But we will not be able to draw conclusions until version 1.0 (currently stable version: 0.70)
Honestly given how amazing the game is, I have high hopes for the dev(s) pushing it to greatness all around.
I just faintly remember slime girl's plot in the beginning being painfully slow until now it's really good.
I do hope they can expand on each plot-line over time, as I feel certain plotlines are either at the mid-point or only getting started.