I say ‘small’ as I consider polish getting a system from 90 percent to 100 percent. But really, that last 10 percent takes just as long as the first 90. Polish is no small task; it is just about small unseen things.
Fine-polishing an animated sequence is an often underestimated expenditure, and so adversely affects many an ambitious project. Read the rest at Gamasutra. There’s also an interesting mention of the dangers of meandering, another issue I often badger my students about.