Upfront disclosure: every positive review about this game is review padding made by bots. Check their past reviews; you'll find nothing but this game and no written reasons why it's good, because it isn't.
Pokemon Legends Z-A is a bad return-to-form for Mega Evolutions and the formula being borrowed from its predecessor is too reductive for gameplay nuance. Mega Evolutions in this game were designed with spamming in mind, so battles are formed around making them the standard instead of special. They are no longer 'stronger' forms; all other Pokemon are made unviable. Very much the 'safe' options for having a Mega-based meta that doesn't have to be committed to by a mainline game, but that makes Megas and the return to Kalos a novelty that invited mediocrity.
The models that aren't for the new Megas are still being recycled from previous games, the graphics are lackluster, Lumiose City is small and boringly samey, the real-time battles are just hack-n-slash slogs, and all of these issues plus more REEK of created problems that the solutions can be sold for. Specifically, as hooks to make the Mega Dimension DLC seem more tempting.
And that's only the hopeful sentiment; the 'fixable' problems may not even have sold solutions, and this game will have been an easy write-off. An easy high-price, low-effort project that's just another case in the study for how many more times it can be done in a row.
Returned after finishing; what a waste.