You can add spell runes to items to give them magical abilities. Spells themselves are combined with keystones to modify their basic traits. A Fireball is just a Fireball, but throw in an Extra Range keystone to fling it further or an Extra Effect keystone to fling it harder. Or better yet, stick it in your favorite sword to add a flame attack when you hit someone. Unfortunately, the magic system falls prey to the frustrating difficulty progression, since spells are less effective as you face increasingly powerful monsters.
Spells draw from stamina, which drains far too quickly to make magic users viable in combat.
Enemies, on the other hand, have a limitless pool of stamina. Stamina is used when you run, so it's impossible to escape from a fight since you're running from something with a bottomless stamina supply. In fact, without boosting your stats somewhat, you're liable to find yourself in the embarrassing situation of being unable to run down an archer who keeps stepping back to shoot at you. Evil Islands does use a good-looking graphics engine to occasionally good effect. The third island's desert cities are particularly impressive.