Finished the first act of a science fiction story at 42k words. Instead of just writing whatever comes to mind I actually outlined the whole story this time, but now that I've written Act I it feels very linear, and I want to expand outwards and write more scenes that convey a bit more about the characters involved, as many of them get introduced, maybe get some characterization at that point, and don't really get explored.

Is this a common writer thing where you feel like you're cutting out too much superfluous dialogue that would serve to enrich the characters? Should I go back and add more or just keep going and seal the deal?