the beds were horrible, the mattress kept sliding off the base and they were generally uncomfortable, the room was so small that once my mattress moved over a few inches it would block the bathroom door.
there's no air conditioning, they supplied a pedastal fan which was noisy and did almost nothing, there's no airflow in the room, the only way to cool the room down was to open the door to the street which just made it incredibly noisy.
we were on the 4th floor, there's no elevator, the light on the 3rd floor is broken so in the dark it's dangerous.
despite booking for 2 people they gave us 1 coffee pod for the machine. there were signs in the bathroom to indicate that there was supposdly some spa aromatherapy things (bath salts?) but no sign of those, there was a guide on how to use the soundbar, but there was no sound bar.
the balcony furniture consisted of a single wierd plastic rabbit shaped thing, which i guess you could sit on?
the lever that connects to the plug in the sink was broken, i reported this to the property 2 hours after checking in, we never got a response the whole time, it was still broken 4 days later when i checked.
this hotel is maybe one step up from a hostel if you don't like talking to anyone or having any kind of human interaction - the checkin process is fully automated via a kiosk at the front door.
we moved to another hotel and had an actual relaxing stay in Cologne.
i now understand why the only options for this hotel were non-refundable.