Not bad.
I pretty much expected a completely unoriginal collab part consisting of just some guy running into a random building. While that's pretty much what did happen, it's admirable that you at least gave it a mildly interesting story. Typically I judge Madness tributes primarily on originality, but this was animated pretty damn good. The main character and the rest of the henchmen looked kinda cool, but it was disappointing to me that the big bad guy behind it was just a normal ATP agent.
The lack of original artwork or straying from Krinkels' style just a little bit was a pretty disappointing, but expected feature of the movie, which is pretty much where the two stars have gone. Don't get me wrong, it's animated pretty damn beautifully, but I've lost much of my appreciation for movies like this. I've seen too many collabs.
While this may not matter to the newer fans of Madness and you'll probably dismiss this as nothing, it's definitely good for us long-time fans to see something we've never seen before. It may also help out the new Madness fans in the future by giving them the idea that originality and creativeness is a major plus. I predict that Madness tributes will eventually become a complete blur, which is pretty much what's happened already actually.
But yeah, that's my complaint. Other than that, beautifully and smoothly animated, nice choice of music, an interesting (even if minor) plot, and a good comeback after your hiatus.
Welcome back.