I'll divide this review into two sections. One for the point and click veterans and one for those who haven't played it before.
For the new players first:
Loom is closer to being a point and click than anything else adventure but it is unique. There are no inventory based puzzles, and only a few conversation based puzzles. Instead your character makes progress by casting 4 note long musical spells. Figuring out which spell you need can be as challenging as many traditional point and click puzzles.
The game is short but it has a properly charming storyline set in a completely weird fairytale-like universe. I think that alone is enough to make it worth its price. It also has 3 difficulty settings since a lot of the game is based on music. So it doesn't matter if you're tone deaf, pick the easiest setting and you'll not lose any of the game.
Reasons to play it... In spite of its age, Loom has a truly arresting atmosphere, an intriguing and mysterious plot and great atmosphere. The difficulty settings allow anyone to play and enjoy it.
Reasons to not play it.... very few... if you can't handle outdated graphics, if you only like object based puzzles... and you really need the sound on so don't buy it if you hate Tchaikovksy. The background music is mostly Tchaikovsky.
For veterans such as myself:
This is a very faithful update that has caused me no trouble working on modern windows machines.
There has been some very decent voice acting attached to the game. The only negative is that the inclusion of voice acting meant that the producers had to cut down the dialogue so what was already a short game is even shorter.