This should be used as the next preloader that's standard to all newgrounds games! It only needs the minor line showing on the one building fixed, but you said that's a frame problem so it can pass for now. Heck, it doesn't even appear in the square area around the tank so it might even be perfect as it is!
Reviews for "NG Tank"
Stylish Fan
It looks amazing! loveit dude:3
It's easy to be overly critical when you have to spend so much time looking at the material in detail when making stuff I know I do this a lot myself when I work in flash and photoshop and every little pixel has to be perfect of I'm just not happy. This also adds tons of time to my projects as a side effect and I need to practice letting go of perfect detail some.
In short the loop looks perfectly smooth to me and probably most people who see it even if you can notice the break your self. This is great quality so just keep doing what you are doing man.
5 stars love it