A battle against gods will be cool, but it requires a lot of special effects for it to be cool.
Also, the focuse is that you are not trying to kill each other, you are trying to control the world. By destroying it... The land starts peacefully, and you build your station of life here, they build their station of death there. As you expand you encounter the chance and opportunity to destroy their world around them. Building volcanoes, launching blizzards, rending the earth to your will. Till you sap the other god from all power and ultimately leave them with the control over a smoldering hump of glass.
The ultimate battle is not between the gods, but between the mortals with godlike power to destroy the entire world or heal it in the process. Without the special effects and the grandiose spell like powers, the game will turn to be a simple slap to the face... ow... slap to the face... ow... slap to the face... ow... repeat until thoroughly bored.
This would be more of a goal to achieve with heavy magic usage.