I really like the mechanics and theme of this book! Its less Dungeons and Dragons and more Dungeon Meshi. Where wounds or equipment do not matter as much, but social interactions and taking care that you don't overexert yourself matter much more. Like there really is a mechanic for when two PCs sit down and talk about their feelings!
The Playbooks (character classes) also feel nice. Everyone is an expert at their own little world of feats. This way the PCs can tackle the adventures from different angles, and maybe help each other. Its somewhat asymmetrical as well. The magic a druid uses is fundamentally different from the magic a magus uses. Its not using the same spells or spell slots or something.
I like the corruption mechanic. You only get corruption from things you yourself do (not even by hurting people, just by HURTING people for example). It never vanishes, so you must be careful not to dive too much into the deep end. And it puts a soft limit on the shelf life of heroes. You have to be really careful in your adventuring career if you want to make it to the other character limit, where you max out your EXP and retire as an NPC. That also means that Heroes are mortal and somewhat temporary, always (which is a good thing in my book). Even the goodest of bois have to retire some day.
One possible downside is that Dungeons are more of a set-dressing now. Unless you really really mutate what a Villain NPC is, and how they act. And while dungeons already can look and feel like anything, theres just something to exploration mechanics with like traps, hazards and some encounters, all for some loot. But thats also kinda fine. In Dungeon Meshi the dungeon(s) are also just a cool setting with lots of lore. We never see Marcille open a loot chest and equip a better staff of fireballs or anything. Rather the few Artifacts they find have unique properties - and that is indeed a mechanic in this book!
Now take all this with a grain of salt. I am mostly a DM and I have not run this game yet. Might be a while before I can open a new group for this. But I am very much excited.