I have a big issue with the grappling hook.
How come Master Chief in his full armor weighting ~1000 lbs (~500 kg) can grapple an elite which weigh 3 time less ~350 lbs (~150 kg) and move towards the elite with the elite not moving at all.
The elite should come flying toward MC, this is basic physics and it ruins the whole idea of spartans being heavy/tank like armored soldier.
The player should feel the weight and the power of a spartan: if a spartan grapples an elite, the elite moves and the spartan holds his ground.
It would have helped also feel the weight of brute and hunters as they are the only enemies which are heavier than a spartan.
That would have been a much more interesting gameplay mechanic to have the grappling hook behave differently depending if you grapple a grunt, an elite, a brute or a hunter.