Having played Nemesis, versus Jack the Ripper, and Testament of...Holmes, I have a soft spot for these games. I've liked the style since I first played Ripper and continue to enjoy every game that I get into from this series.
Nemesis finds Holmes pitted against Arsene Lupin, (a character of Maruice Leblanc's writings), the gentlemen thief. While one could argue this way and that to the justice to the true character of Lupin, I think that misses the point.
I found that the puzzles in this game are more enigmatic than those of the other games I have mentioned solely because Lupin is such a character. I feel that the puzzles and tasks that lay before you as a player are cerebral and push you to observe everything. In a sense, it is pushing you to be Holmes. Though I may have groaned at another failed attempt at a puzzle, the sense of reward after finding the answer on my own was exceedingly gratifying.
What Holmes game would you want to play that readily gives you all the answers? I don't want one of those. I'd rather sit and ponder art puzzles or move around a giant library to find the clues I need to complete each mission/task.
If you're looking for a game that is easy and entertaining to pass the time, this may not be the game for you.
However, if you are looking for a game that's going to push you and test you, have great history, and by chance have you learn something in the process, then you should give it a go.