Murder Mansion was a great room - if you’re in the Lexington area, I would recommend this room and Ghost Town as must-dos. I rank this as a low love / high like, rounded up due to the great experience and lovely staff.
The concept is that you’re a detective re-visiting a cold case in a mansion to figure out who the murderer was.
The puzzles were all fairly fun and interesting (I think my favorite was the room with the twist and getting to listen to the stories, really well done and fun).
One of the puzzles was a bottleneck (maze). I assume this is a bit of a timewaster for most groups, as they label where you need to start/go through/end to get where you need to go. We overthought the hints a bit. I didn’t dislike this puzzle, but did think that it could be shorter. We had one person doing it by themselves and the other four of us were just waiting for it to finish.
The door puzzle was really unique, I’ve never seen a puzzle like that before. I thought it was fairly fun too and the reveal to the final room was really awesome!
The final puzzle does require some math skills. My partner and I are apparently math beasts and got it fairly quickly.
I would recommend a good number of people for this room. Besides the bottleneck, the first puzzle in the last room really needs someone reading, someone completing the puzzle, and ideally one person in two other rooms figuring out what the clues represent. We did with 5 enthusiasts and I thought this number was appropriate and we finished with about 6 minutes left.

Kalli was the person who introduced us to most of the rooms, but everyone at Countdown was great!
Particularly interesting or different
Yes
We played with a group of 5 enthusiasts and I think there was just one real bottleneck area.
I think it’s mostly kid friendly but it’s themes of murder.
Physically active
Somewhat
One step of stairs (that several people need to step on / having one person step on in sequence) and a crawling portion that at least one person needs to go through.
Accessibility
Stairs and a crawling portion. Think both could be completed by one person if needed.
Parking lot directly outside.