A fairly short game, but fun while it lasted.
The game is based on the novel of the same name by Sir Arthur Conan Doyle, involving the disappearance of a famous archeologist. I have never read the book, but the mystery told by the game was very intriguing. However, during certain cutscenes I was confused by what's going on, as they felt very disconnected from each other.
There are 5 levels in the game, each level serving as a chapter in the plot, and the difficulty (and the number of items to collect) increases after each. Even so, this was a fairly short game, as I don't think I have spent more than 5 or 6 hours on it.
Mystery of the Mummy wasn't a hard game, but it was by no means easy. Most of the puzzles involved exploring each area and find all the necessary objects in order to solve puzzles, but often it isn't quite clear what you are supposed to do.
The music I thought was rather fitting, but they get repetitive after a while, as it's the same thing playing over and over again in each level.
Biggest problem for the game is the graphics in my opinion. I understand that it's on a DS, but everything has such a grainy texture, oftentimes it's hard to make out an important object among the other things in the background.
The touch interface is not bad, there are an occasional lag here and there, but overall it's pretty responsive, although sometimes slightly over-sensitive.
The ending bugged me slightly, as Sherlock Holmes was trying to explain the whole plot and explain who the culprit was within 3 minutes or so, and it was too much to take in for someone who has never read the book. There was no credits or anything like that either, so it was over before I knew it.
To sum everything up, due to its length and several noticeable flaws, you should probably rent this game. Not a bad adventure experience, but there are certainly better alternatives out there.