Runemasters ►►► a simple way to improve this fast puzzley fantasy combat card game?

About Runemasters, from BoardGameGeek:

Runemasters is a co-operative tower-defense game in which 1-4 players work together as Runemasters whose sworn duty is to protect the Temple of Mankind against the forces of evil. Each turn, new monsters (cards) spawn on the board and advance towards the temple. On their turn, Runemasters roll four unique dice and combine their results in various ways to attack enemies, move around the temple, prevent monsters from advancing, use their individual powers, or trigger powerful one-time effects. Evil forces are relentless and will keep coming until dawn arrives. Werewolves, warriors, skeleton archers, trolls - all have their unique abilities, and you need to adapt constantly to new threats if you want to have a chance to survive until dawn. Runemasters have their own abilities, too, some particularly efficient at eliminating enemies while others focus on healing and protecting their teammates. The game ends in victory if Runemasters successfully protect the temple until dawn (a special card placed among the final four cards of the deck) or in defeat if the Runemasters are killed or the temple destroyed. -description from designer