I bought all SH games and decided to start at the beginning, and I'm very disappointed. And yeah, I know this game is old but that is not a very good excuse.
You can only play it at fullscreen (in which everything is pixelated and hard to look at - and I only have a 13'' screen, which is considerably small), you can't alt+tab away from the game unless you're in for restarting it (you can't even access the Steam layer) and it happens a lot that the game crashes at cutscenes (that stuff you spent the last hour working on? Lost!).
If that is not enough to harden your way through, items are very very well hidden, which is not a bad point per se, but I found they were just overly hidden for it to be fun. I don't know whether this was made on purpose (since Sherlock's primary skill is observing it makes sense to make it hard to "see" useful stuff) or not.
Also, the puzzles are really difficult (difficult enough they're no longer fun) and most of the time will require you take paper and pen (since you can't alt+tab out of the game) and spend some long time on them, which could be fun if you like it (like I do), but, in this case, it just isn't.
Yes, the story is fine, the way you can get letters (backstory) is well thought of, moving through rooms/levels is a very good mechanic, but the bad points weight, by far, much more than the good points.
So, unless you enjoy very difficult and time-consuming games, don't spend your money on this.
If you get this in a SH bundle and need to check it out just because you're a fan, don't be afraid to have a walkthrough ready on your phone!