Long Ago, Etheria was once a land of living legends… Throughout the ages, brave warriors across the realm stood together against the forces of evil, led by immortal beings known as the Old Ones… After a titanic struggle, these champions locked away the power of the Old Ones, inside Eternia Crystals…These legendary heroes have recently left their younger kin in charge of the common castle chores… Bored with their dreary duties, the inexperienced pupils decide to play… And accidentally unleash an ancient force that has long been dormant!
Great Co-op tower defense RPG!
There is a high barrier to entry as having a friend power level you is the only way to prepare for nightmare difficultly in a timely manner.
Some of the end-game content is ridiculously difficult, and drop rates on good items are so low that it can take forever to prepare for it.