When a character is free to move about in two or three dimensions, there is a tendancy to lock the player's direction of attack to the player's direction of movement.

However, this makes the game more difficult for the player, since the only way to attack an enemy is to move directly towards it--which also happens to be the line of its attacks towards the player.

Therefore, make at least one attack independent of the player's direction of movement. This allows for indirect attacks akin to "drive-bys".