I read it a few years ago and genuinely thought it was good, but I agree with what people said before - it's heavy, really heavy. The story itself (narrated by Death, set in Nazi Germany) is engaging, but the tone is melancholic from start to finish. If you're the type who likes to fully immerse yourself in an atmosphere and doesn't mind reading that leaves a certain weight on you, I'd recommend it. Now, if you're short on time and looking for something that leaves you feeling upbeat at the end, it might not be the best choice.
My practical advice: before you buy the physical book, grab a sample on any platform (Kindle, Wattpad, even libraries have previews). Read the first few chapters and see if Death's voice appeals to you and if you can handle that slow pace. It's a book that either grabs you early on or falls flat. It's not one of those that "gets better later" - what comes next is more of the same, just with different layers.