Hotkeys for skills: 1, 2, 3, 4, 5, 6 allow for enemies to be slain.

Don't forget to upgrade your attributes (bottom right)

Every attack or movement provides action points to all enemies. With enough AP they can attack or move in turn. Thought of another way, each movement takes time, some take more time than others. Spend your time wisely or counter-attacks will be your doom.