I got in the firetruck and accelerated a little before getting out. The truck sped up and flew off the edge of the map to my dismay haha. I tried again, and I can see what you're going for. I think this is quite a cool idea, creating an ecosystem of fire defense with water management could be quite fun. I struggled to put out the flames fully, and wasn't quite sure at what point I was getting rewarded with money. I think this game could particularly use a tutorial, and maybe as you said, a bit more polish to avoid the bugs that come with a complicated system like this.
I liked what polish you had time to get in, the menu and transition felt really nice and smooth, the water physics seems to work well and putting out the fire was satisfying. Art was really nice, everything fit together really nicely, would love a pause menu though haha. Great job, I wouldn't be surprised if you wanted to continue working on this.