I speak as somebody who has tried four different room escapes in the GTA. Mystery Room is not recommended by any stretch of the imagination.
My group and I did like the fact that each challenge involves multiple rooms and there were some interesting physical puzzles.
We were disappointed with the overall quality of the experience, though. The rooms and puzzle objects felt old, used and generally run-down. There was at least one hint hidden in a rather out-of-the-way place, but with room corners and the undersides of furniture covered in cobwebs, the prospect of searching was rather off-putting.
I think the logic structure of the challenge was also disappointing. There were complete red herrings all over the place, and again, as a person with experience, I have completed rooms that were difficult without resorting to distracting players with superfluous things.
For anyone looking to room escape, I highly recommend looking elsewhere -- there are much better offerings in the area.