If the game crashes when selecting a skill just upgrade adobe flash version and it will work. it becomes much easier with mega heal and can't-miss-hits :)
sage880, i'm beating hardcore easily with 1 cleric (max endurance) in front and 3 mages in back (max intelect). the strategy in the first levels is just to use cleric as tank while mages level up and get electrical storm and cosmic prison (for emergencies). later u just kill everything after 1 round of electrical storms so ull eventually switch to life regen and later to quickness.
some comments suggest 4 mages since u would only get items that work for you (in "my" strategy u get 1/3 heavy items for cleric only, and 1/3 medium items that is pure waste). it proly should work if 1 of the mages replaces cleric and maxes endurance to "tank" (and u would eventually need to actually use potions much more often, but later levels will be walk in the park)