Who says they can't make a good prequel? I think the Tankmen series are great, but they're not one of my favorites. I just find other stuff to be funnier. This really did work well as a prequel. We get to see how they recruit people. I never even thought about that.
The easter egg (deleted scene) is on the ending credits page. Just click the two guys at the bottom. I'm sorry I can't remember their names. Did they even have any? The animation is great too.