Both the overworld and mansions have middling to poor level designs, especially the mansions, which tend to be overly reliant on finicky jumps, frustrating enemy placement and conveluted level design. CV is no stranger to tight platforming and annoying enemies, but it shoots past challenging to straight frustration due to how sloppy it is. All the mansions look the same with a slight change in color, and the overworld, which has slightly more variety to it funnily enough, is still pretty similar all around, making the game visually boring too.
Illusionary platforms you have to throw Holy Water at to see it's real or not is an massive annoyance that adds nothing. Same with the day night cycle, which pauses the game every single time it happens for 5 seconds. The game not telling you what to do in any way or form makes it a complete trial and error whether you are able to progress or not. The NPCs are mostly unhelpful, making a game that has poor direction even poorer. Good luck completing the game on your first playthrough without a guide.