In addition to the main tasks, there are also secondary quests. They are not very original (mostly kill, bring, and other tasks), but the reward for completing them will be artifacts, increased hero stats, or other useful items.
The events unfold rapidly, and you won't have time to be distracted. "Flame of Vengeance" will definitely appeal to fans of challenging battles who will have a place to demonstrate their skills, but even those who just like to play "Heroes" will be satisfied.