This is looking really good! My only suggestion is that I think you should add some pilots that drive the tanks (or at least are associated with the tanks). If you look at a game like "CATS: Crash Arena Turbo Stars" from ZeptoLab you can see how much character they added to an otherwise sterile "junk heap" setting simply by putting some emotive creatures in the tanks that smile or cry when they win or lose. They initially didn't have these cats, but they realized in early gameplay testing that it's hard for people to latch onto inanimate machines. Even their other physics-based puzzle game hit "Cut the Rope" has a cute little guy who eats candy. The game doesn't need him, it could just be "get the orb into the trash bin". But having a cute little guy to interact with is far better. Even if you added eyes to your tanks ala Pixar's "Cars" (or "Super Mario Odyssey's" Cappy), would go a long way for players to grow some attachment to their tanks. This isn't even a game design thing, this is a human thing. We love anthropomorphizing everything... People like birds in their mobile games (Angry Birds, Flappy Birds, Tiny Wings). Maybe have a Commander Bluejay and Captain Sparrow? Little tank commander hat on a bird... I dunno. Just spit balling.