The art is fenomenal, the MC is actually someone that has been doing his stuff for years, so the knowledge feels deserved… the story starts declining for me in the current evolution, as there is plot armor that’s not explained… the mate can literally be a normal person now, and I feel that his goal is too generic, doesn’t matter the generic past either.

It’s fine, I enjoyed reading it, but I won’t keep up with it.

If you want a fantasy adventure you can't go wrong with this one: The story generally progresses at a comfortable pace; it doesn't try to stuff in a million different characters and instead focuses on developing a strong core cast; the fantasy elements are interesting and they take their time discovering more and more elements of world building that fit in with the rest and are relevant to the story when introduced; solid art style and attention to detail; has some pretty funny rom-com moments sprinkled in to ease tension at certain points in the story.

It still has a few flaws like: some of the later action scenes seem like they drag on a bit too long; the protagonists long term motivations and background are revealed a bit late; a few pretty extreme coincidences (which end up having a huge impact on the story but happen very rarely and are still believable); some characters attitudes towards the protagonist are very extreme and the explanations for "why" feel insufficient; sometimes the rom-com scenes temporarily push the characters to extreme versions of themselves.

Overall the positives FAR outweigh the negatives considering the negatives only show up a few times per volume and the positives fill every page.

This one has some very good points. Above all, I found the world building skills of the author to be great, he takes the trouble to explain things an build a believable universe. As a result there are some lengthy explanations and a lower pace but imo it's worth it for a consistent world.
This kind of seriousness is also reflected in the character, even if the MC is not particularly great, his story is interesting and there are no ridiculous power-ups or OP crap, there are rules (some unknown) set and the progression respects those boundaries. Likewise, the MC is not from an isekai, nor is he in a novel or has gone back to his past, his advantage are those given by his new condition and his wealth of knowledge from having been an adventurer for 10 years and having to resort to information and study since he wasn't very strong, this consistency is sustained in little details, like him not knowing about things he has not yet encountered, he is no "know it all".
As for story, so far it's just the MC's story, which, as said, I find interesting, from ch 25 or so a new plot is brewing but it's too soon to tell.
The negatives are that even though the art is good, the fights flow ain't particularly well done. Also it's very Japanese in regards to romance and such (like mecha-like golems), I mean this in their characteristic naiveite, the author tries hard to be serious and the chars are mature, but they become childish all of a sudden in romance and I could imagine the mazinger or gundam song in the background with the golem... oh well, it's manga.

I absolutely ADORE this story and agree with all of the points that @Killerthug makes.

Well fleshed-out (heheh) world with well-interacting characters. Progression is good and MC isn't just OP- and not TOTALLY the opposite. There is a good balance as he slowly learns his place in the world.

Read if you enjoy 'I am stuck as a [insert monster/creature] in an isekai!!' story. This one ranks highly among them.