Good? Yes. Great? Not quite.
Firstly, I have never been overly keen on the FPS genre as a whole, making me, perhaps, a little biased before even inserting the disk. This is exacerbated, however, by the fact that Halo seems to offer nothing different, the 'super soldier versus the alien horde' plotline is cliched with only a few curve-balls to alleviate the mundanity of a hackneyed story. Furthermore, the gameplay is solid, not groundbreaking or incredible, merely acceptable, right trigger is shoot, B is melee, left trigger throws grenades, that's all you need to know frankly.
Admittedly the levels are enormous, and the scope of the game is frequently impressed on you, leaving a indelible mark. However, whilst the outdoor levels are breathtaking and pleasing to play through, the indoor areas suffer from overbearing greyness and monotony.
Finally, the game is difficult. Not that this is always a flaw in a game, indeed, it can be enjoyable when your own efforts are countered by those of the computer's A.I. Conversely, it is a flaw when the difficulty is maintained via sheer force of numbers, and you are forced to slog it out against limitless foes who overwhelm you, as opposed to outmanoeuvre you.
To conclude, whilst my review may seem mainly negative, i have no doubt that avid FPS fans will adore this game and with good reason, but as a fan of other genres i find myself ultimately unfulfilled by Halo: Combat Evolved.