I played the game several times and I'm still not sure how exactly the heat system works, although I think the idea is pretty interesting. If done right the risk vs reward of increasing heat to deal more damage but risk to be blown up could be pretty nice and challenging. What I found a bit limiting was the fact that I can only shoot straight forward. I think it would work better if you aim with your mouse in any direction you want while driving the boat. Then you could even add mounted weapons that can only shoot 45 degree or so to one side. There is potential :)