European colonialism was certainly novel in its sheer scale, and its effects are felt to this day in pretty much every non European country barring a small handful.
Less economic dominance because they were nomadic raiders not traders or industrialists.
Their complete cultural apathy is largely what makes them "not colonalism" technically. In the same way that samuari aren't technically feudalism because they aren't landowners but servants of a lord. Although they work by analogy pretty well.