This is really good. Every set piece looks like it belongs and has its own place in the short. 3D animations have a way of making space lose its sense, and distances get muddled, but here, everything was consistent. It had a bit of a slow start, but it was necessary to set up the rest of the movie.
Speaking of pacing; good job. It started slow and the first action scene had a lot more going on to compensate including a Golem to set the stakes, the next scene had less going on, but it was faster, until the fight with the twins in the store, where it was simple, but very quick. Then the Golem comes back leading to a stand off where Hank always has the upper hand, but can't quite take down the tank. After succeeding, the reveal of Jeebus keeps us wanting more.
The technical skill is obviously on center stage here as every movement is accounted for and every action has weight. The texturing and camera movements looked a little game-ish, but considering the source, that's actually a positive.
Comparing this to other fan works, this one seems like it would actually fit in with the main series (sans the extra dimension), whereas the others I've seen are often too serious. The original works were comedies that happened to be violent, and even then, the blood actually started pretty late into the series. The backbone of Madness is the levity of it, and the few breaks for that in the shop and the opening scene were evidence that you recognized that.
Anyways, enough of me rambling. You did good, and your work will be appreciated by anyone who sees it. I hope to see more in the future, but after 2+ years on this one, I could understand you taking a break.