Jean-Luc Dinsdale from InsideMacGames has (predictably, if also accurately) gushed about Halo on the Mac, calling it "the most advanced, the best produced, the most amazing first-person shooter to have ever graced [the] Mac". (All you Half-Life fans, make sure you read that last part carefully.The four-page review is quite thorough, but overall they give the game a 9.25 out of ten (what are they using, the Richter scale?) The review also ends with an important note for those who haven't yet gotten over the Microsoft buyout:

And, before our readers start sending the inevitable torrent of angry emails flooding my way, I urge any and all bitter and ungrateful gamers who still carry their grudge against Bungie after all these years, to stop for one second, put your emotions aside for a moment, and take a fresh, unbiased look at this game. Underneath the blue and white Microsoft logo you'll find a game that was the heart and soul of the dedicated, talented, and extremely hard-working Bungie Studios team whose games you've enjoyed and relished for years. And for that reason alone, Halo is worth buying.

Sound advice. On the con side, IMG does note the "repetetive design" criticism (hopefully no more of this after Halo 2) and the high system requirements.