I was quite late to this party weren't I?
Warning: this review was written by a nerd who read both the LN and manga, and as such, comes from that perspective specifically, grading it as an adaptation.

First impressions matter, and this anime does first impressions really well, it looks astonishingly good, the colors are wonderful, characters all feel so lively, it has a distinct style, it's great. I also love how it interweaves the openings with the show itself, it allows us to get a feel for the world and location we're in without the show having to stop constantly to present shots of the locations the story's taking part in. The character adaptations are all also pretty damn good, Paul and Eris' family look a bit off somehow, but apart from that, everyone looks exactly how I imaged them reading the LN, and that theme of being a great adaptation also carries over to the rest of the anime.
It gets the tone really spot on. The voice actors are all great, especially Rudy when presented in an opposition between his outer and inner self.
The story's Mushoku Tensei's so I really liked it, though I would've liked it even more if instead of removing a lot of the minor sex jokes, they removed a lot of the major ones, I get why they didn't remove Roxy's panties or Rudy's birthday, but apart from those two, the rest were really unnecessary. The pacing's also great, though there are definitely some things I feel could've been cut more (like the sex and Rudeus' real life during the first episode) and things that deserved more time (Paul's fight scene and Rudeus' inner troubles with the idea of straight up killing people), it just flows really nicely for the most part.
Though I do have 2 critics about it:
It's music. God damn, that is one underwhelming soundtrack, for all the details in the animation the choice of voice actors and adaptation work, I really expected music that stood out a lot more, but this just felt like "music" I have no real thoughts about it, it was just there.
Mangod. I feel so conflicted about him. His voice actor was great, his story is done well, however, I think his representation is really weird. The studio went for a human body in pure white, which is fine, but it's somewhat unclear while still having a clear shape and all. I feel they should've been a clearly human body hidden in mist or something to make it so you can't see his entire body at once or an extremely unclear or generic body shape, cause that's what he's suppose to be, unclear, Rudeus commented multiple time in the LN about that, he literally cannot tell what Mangod looks like.

Mid 7. Amazing adaptation and still great as a standalone anime.