If you're a fan of puzzle IF, then the other reviews pretty much cover it - you'll probably enjoy this, and don't let anyone (least of all me) tell you otherwise!
But I found I didn't - I'm not a beginner exactly, but I mostly skew towards Story IF. Plotkin's writing is crisp, and some of the scenery is certainly compelling. But I found myself getting bogged down in mapping (all the non-cardinal directions like NW) and the puzzles. There's a hint system, but it rather primly stops before giving an unblocking suggestion too often.
After resorting to a walkthrough about (Spoiler - click to show)the order of masks at the mirror, my reaction was a slightly irritable "Huh? How was I supposed to figure that out?" But that's ok, this just isn't for me.
Clearly lots of people love these puzzles, but if you're not one of them, please don't despair: there are other styles of story to explore.