Just some of my guesses:
#1: Schizophrenic and criminally short - One minute you're fighting on the ground, the next you're sneaking about with a sniper rifle in the shadows, the next you're in space, then you're on the ground again, then you're flying about in a helicopter, you're on the ground again, you save the day but not really, then you get called ethnic slurs by twelve year-olds. All of that in the span of 7 hours.
My view: Generally I enjoyed the varied gameplay as it kept the game moving without feeling too repetitive. However, I do have to say that Reach felt very short considering how much you would think would be going on. Certain points like the space mission transitioned so quickly without explaining the gaps too well. To me, the Helicopter mission in particular dragged on while not really contributing to a sense of "time" or progress during the events of Reach. I don't really like vehicle sections, either, and would have liked to have seen more fights like defending Dr. Hasley's lab.
#2: Unlikable/Throw-Away Characters and Plot - I know that I am supposed to have some emotional response other than "Boom! Headshot!", but remind me again why I'm supposed to be drowning in remorse over some trite space marine's bathetic demise?
My view: Compared to the Halo trilogy games, I much preferred Reach's characters and plot. Everything tied in well with the setting, and there was an overarching consistency. My only complaint for plot would tie in more with its lack of length and involvement with the characters.
#3: Gimmicks - An ode to Star Wars randomly jostled into the fray to add another bullet point to the back of the box, while never rearing its head in any other application for the game every again. Jetpacks are impractical contrivances shoehorned in to appease the simple-minded. The jetpack's thrust is as impotent as the collective efforts in a nursery home, propelling you feeble distances that are mitigated only by the fact that you cannot otherwise jump across forced sections in the game. Strategically, it is otherwise a fine way to perch yourself within firing distance of every enemy within 200 yards as there is no cover on the top of a mountain of crates.
My view: I did like the space combat, but would have liked to have seen it used more or even introduced in its own game mode like firefight. The jetpack, well, for single player, yeah... it was not very useful.
#4: While too afraid to abandon the "mend your bleeding ass by hiding behind a rock" health system, Reach also features a nominal health bar system that also regenerates anyway, relegating health packs to the usefulness of jetpacks attached to the undercarriage of a tank.
My view: Going back to the Halo trilogy, Reach and CE are the best in my opinion, as the health bar adds to the experience and gameplay. I still don't understand why the health bar would also sometimes recharge, though.
