One strong argument for hexes was that they add more depth to combat. Six sides are just better than four.

Reason one: Movement costs are more obvious. The distance from any position on the hex grid to the center of the next position on the grid is same for each of the six adjacent hexagons. There is no diagonal movement to an adjacent square that only touches the field you are currently on in a single point instead of sharing a side with it. With squares you either have to make diagonal movement cheaper (and thus preferable and exploitable) as moving two squares to reach the same diagonal one or more expensive than moving a single square. With hexes you move one field and it can always be the same cost. If you have played D&D 4th Edition (which will let you move diagonally at the cost of one square) you will know the urge to exploit that apparent “extra ground” you can cover by moving diagonally. We felt that in a video game where you want to simply point at your target field and have the character move there it was easier to calculate the path to go.

Reason two: With hexes you can have a clear facing into the moving direction. With squares you either have to start implying that it is actually an octagon you stand on and you have eight directions you can have your character face in or make facing be irrelevant (as D&D 4th Edition did where it is only relevant that two enemies cover opposing squares adjacent to the one you are standing in). We wanted facing to be relevant for actions like backstabbing since trying to get into the back of another character (or trying to make sure the back of your own character is covered) adds more depth to the decisions made in combat.​