These are more so extended personal notes rather than a thoroughly planned review, so it won't be exhaustive.

First of all, this passion project is a small miracle of animation (especially considering it's short staff) and, needless to say, it's hilarious that this aired together with Blue Lock's 2nd season (it goes to show how badly big projects can fail). Unfortunately, however, the art style of Mecha-Ude is cut down to the bare bones of absolutely essential lines of objects, giving it sometimes a very "flat-land" feeling. Yet, to some extent, this is done to account for the constantly fluid and clean animation. There is definitely no static scene in this show — your eyes will be busy. Admittedly, this can cause some scenes to have poorer readability, but I would also nitpick this about any show with busy animation, so this is not much of a problem.

On another hand, it's kind of unsettling how there is next to no shading throughout the show. Still, the detail given to movement, both from the camera that rotates around to cover the entire playing field of the action, as well as from the bodies and objects themselves, is a fair artistic choice. The show also gladly received Hiroyuki Sawano's music, which, albeit nauseating at this point, cannot fail to push an anime's presentation a few steps up in score. Being emotionally invested in the fights is generally not a problem. And I could not skip the catchy OP even once!

Furthermore, everything about its inspiring atmosphere and the vivacity of its characters (brought about mostly by their voice actors and how they deliver some amusing dialogue lines) grants the viewer a generally positive experience; though never quite chilling. Sadly, the runtime for this series is too short and poorly used. It provides no real statement about anything, while also leaving us with characters that are too simple to be worthy of mention (if charismatic). Our protagonist is an "unchosen one", who is thrown into a supernatural situation and just happens to be too kind to walk away from it — even when everyone else tells him to.

This heroic character works along with Alma, the most important individual out of the Mecha-Ude creatures, since he holds a fundamental ability for their grand objective of reestablishing the Mecha-Ude's previous status quo of reality, and thus, in the process, also free themselves from certain groups of humans who aim to control and suppress their minds. Naturally, you would expect some themes of oppression, deception, coexistence of living beings, friendship and heroism to result from this setting. And they do, but they are all helplessly cliché — you might have already figured out some of them in your head just from reading this. If you watched shounen anime before this show, you have watched this show. It cannot stand out.

For instance, the Mecha-Ude are presented as alien-like sentient beings, but those beings are incapable of being anything other than humans (with a different skin). Their behavior and thinking is too anthropomorphized, to the point of being ridiculous when it comes to certain characters, such as Ayumi. Not to spoil much, but imagine a stereotypical futile high school girl, speaking in modern slang and acting all chatty; this is exactly what she is, despite having lived for who knows how many centuries (and, until recently, being stuck in an indefinitely long slumber).

The plot is also too obvious and unsurprising. It doesn't makes bad diversions, but it also doesn't take interesting turns. Nearly every single thing about it is predictable, to the point that I genuinely cannot talk about it without risking spoilers. It follows the shounen sci-fi formula too close to a tee. With that being said, in terms of story and characters alone, this show is skippable, unless you're a fan of some fun, action/comedy driven sci-fi anime who is looking for a comfortable watch. As for the production side of things, with its hand-crafted and ambitious nature and quality, this underrated piece very much deserves a chance.