Thinking of changing the objective. What do you think?

What if instead of defending the tower, your goal was to destroy the tower and the creatures were defending the tower from you. The tower guns act as turrets against you and you drive the tank around to build walls, shoot and even hover.... I wonder if this would be more dynamic and interesting.

I feel I am at a crossroads - Make it better or start again anew.

Making games is hard, yes?