Great game! Honestly a lot more in depth than I was expecting.
My main complaint is that it's a very frustrating game to parse at times. It's very unclear where to go sometimes, and the labyrinthine nature of the game with no map makes it kind of annoying when you want to revisit somewhere but don't remember the exact route, or forgot which places you have and haven't visited yet. Even as I'm writing this review having explored everywhere I'm forgetting how to get to a lot of places and don't even want to try loading an old save to serve each deity because it'd mean wandering around to remember where things are even when I know what I need to do next.
Additionally the music box quest felt kind of pointless and the reward for valac shards felt massively underwhelming as by the time I both collected all of them and figured out where they go I already had all the books that told me how to and already managed to kill the bosses minus the final one, which the hints didn't really help at all for.
Despite all that I still pushed through the frustration and got to the end and explored everything, which is a testament to how compelling the world is and how good the game feels when things do work! This could honestly be a steam game with a little more polish, longer playtime, and some of the frustrating bits ironed out (with maybe some overworld enemies or mechanics to keep exploration interesting and not just wandering about). Solid game!
----SPOILERS/TIPS FOR TROUBLESOME PARTS BELOW FOR THOSE THAT WANT IT----
General tip - swing your sword at grassy walls in the labyrinth, you can sometimes open up a path.
Spiral doors - get the fan and blow the pinwheels. Forget exactly where but might be near one of the temples listed below.
Can't fight any deities - Requires the helmet of vision then you need to speak to the skeleton guy in the bone pit area.
Can't Find mammon/blacksmith/explorer books 5-7: Forgotten City. In the place where it says "The floor feels unstable" just wait in place for a minute and you'll end up in a new area.
Eye corridors at the end of the puzzle gauntlet - Hard to explain but I basically went with the corridor that had the least patterns on the ground. I remember the first corridor you go down.
Temples - One in the forgotten city, one past the puzzle gauntlet with the stairs where music plays in the basement, down the elevator past the eye statues (enter the order in reverse to open the elevator), one below Antoine's house.
Temple beneath Antoine: come back after you found the stranger on the bench above ground, and again by mammon (might be a third place I don't remember. The library?)