What's the point of giving out bubble points if the HP of a tank is determined entirely by its size class rather than the number of bubbles? Being able to build your own tank is cool, but not if you're going to lose the most fundamental aspect of the bubbletanks game engine engine--the bubbles being both health and structure.
So how did we get a car where the engine and spark plugs are located conveniently inside the cabin rather than under the hood, where you can't get them without being eaten by zombies? Other than that, it's a pretty good game, I guess.