First off, welcome home!
I'm sure you're box is fine, I've sent three overseas from the U.S. to Japan by both air freight (UPS) and as checked luggage on a plane.
Next, don't get the impression that Halo runs "worse" than other games. It's just that you can't compare certain types of games. Halo is a great shooter with a framerate locked at 30FPS, meaning it doesn't apear as "fluid" and smooth as a game running at 60FPS. But it never drops frames (re: skipping, stuttering, get choppy) not matter how heavy the action gets.
If they TRIED to make it run at 60FPS from the start, it would look good most of the time, but would start dropping frames when the action heats up. So in Halo's case, it was a technical decision made by Bungie to lock the FPS at 30.
Now a good racing game (get Burnout 3, it rules!) will usually run at a smooth 60FPS, which makes motion appear more smooth and fluid, but doesn't actually affect game play (like, make the car handle better or whatever). It just looks prettier. And it can draw at 60FPS because there's much less polygons in used in a racer (usually).
BUT, a bad racer, meaning coded poorly, might drop frames and stutter when many cars are on screen,
In the same way, a bad shooter like Mace Griffen just runs poorly to begin with, and has a constantly changing framerate. Smooth when you're alone, choppy when you're fighting bad guys. THAT makes for a shitty gaming experience. You can't aim well at all when you need to most!!
So, to sum up, a good, stable framerate makes for a good play at any framerate around 30FPS or above. A (stable) 60FPS game of any kind looks smoother than a 30FPS game, but stability is the key. Playability doesn't really change.
But a game with a variable framerate (like Deus Ex) that drops frames (gets choppy) when things get busy, will be hard/no fun to play.
Stable = fun. 60fps (stable) = smoother (in appearance) than 30fps (stable). Unstable framerate = shitty game.
Is that clear? I hope your mod goes well. I'll be here.