Could have been decent, but the cheating AI and annoying difficulty make it tedious and frustrating.
Every time you attack an enemy base the enemy will do the same and attack one of yours. By the time you've gotten back to defend that base the enemy will already be attacking a base on the other side of the map. This constant cat-and-mouse goes on forever making missions very tedious.
It's not enough to defend the borders of your territory since the enemy can sail right past those and go straight for your undefended bases in the middle.
Taking over enemy factories doesn't matter since the AI will cheat and spawn new units at the edge of the map. The enemy also sees through the fog-of-war, attacking bases as soon as you move your fleet away.
The graphics are fine, but that doesn't matter since you spend 90% of the time looking at the mini-map.