Feels like a good reminder of reasons why isekais and similar stuff have become the refuge of lazily-written self-insert stories: This is honestly a little stale.
The open-fantasy-worlds of isekai are a blank canvas for the imagination (even if what authors scribble on those canvases tends to be rather derivative); whereas here there's no world-building, no culture-building, no sense of discovery or exploration. There's no underlying sense of yearning or curiosity with which to pad out the whole 'lotta nothingness that comprises this sort of "Protagonist is OP now! Let's invent stuff for him to do!" plot.
It's not exactly bad, or anything, mind. Good old shounen staples, I guess. I'm sort of rather fond of the chill old man cat-god too.
...Oh, also, either I'm having a stroke or this translation is somewhat awful. XD