During tower defense levels, position your tank and their two minions correctly. They minions and the hero will not do that much damage, however they can soak up damage while holding enemies back. This allows other heroes to take them out. Place them at choke points that lead to your other heroes. In RPG combat levels, fill the five slots for your party with a balanced group. Fill them with one of each type of hero (tank, marksman, mage, support, and cannon).
Runes
Use runes to upgrade your heroes. Runes are found in particular levels. Each hero can equip certain runes. After a full set of runes has been completed on a hero, they can learn a new skill.
Wishing Pool
The Wishing Pool rewards you with a gold and diamond chest. Gold chests can contain items, runes, or heroes. You can open five of those types of chests for free each day. Diamond chests can reward you with items, runes, and heroes. Getting a rare hero is also possible. You can open one of those types of chests for free once every two days.