Nope, it’s not a tower defense game. It sounds like plants vs. zombies… or maybe zombie driver but it’s neither.
This is a online only game - although it can be played with bots. The objective for the drivers is to hit the animal mutants or shoot them with guns out the windshield before they destroy you. Vice versa for the mutants. They have the ability to pick up objects and throw them at the vehicles, or like the tank from Left 4 Dead, rip up hard concrete.
It’s simple really.
It’s supposed to be very balanced.
Other gamemodes that should come with this mod is a regular race (vehicles vs. vehicles), survival (obvious), objective (come to a point on the map without weapons while the mutants try to destroy you) and capture and hold the objective. Mutants vs. vehicles again.