Oooh. Nice work. Although, I'd tweak the flamethrower. The V shape that it shoots out.. looks strange to be honest.. and the shaking when it unleashes the flame looks weird.
I'd try and squeeze the V into a more fireballish shape. I'd make the area where it's blue smaller. Regular air pressure would cool the flame, thus making the color blue just barely outside of the barrel.
Besides that, epic work. Now there's the tricky anti air cannons too. Also, it looks better if the cannon itself moves rather the whole tinker turret frame.
When the whole frames shakes back and forth it makes it makes it appear flimsy and unstable. But yeah, a great WIP. ;D