There is very little that is original or exciting in this film. It's a standard modern-day haunted house "found footage" style horror. Some of the spooks amount to silly jumpscares, some of them provoke laughter at how silly they are, and some are so incredibly subtle that you would never even notice if you weren't actively looking for something out of the ordinary.
The characters are fine. The setting is fine. There's a decent enough backstory to the old castle, and all of it is clear and evident and predictable. It still manages to be fun and oddly entertaining. It tries nothing new and gives nothing new, and by the first ten minutes or so, you're well aware of this and thus have the opportunity to bail out early on without wasting much of your time.
The only major complaint I would have is that every single instance of spooky jumpscare or ghosty activity is preceded by very loud and very noticeable on-screen static and video distortion. It makes an already predictable moment even more predictable.
About the only thing memorable for me is this film is German and I do not know German