Well...
It was decent, but I can't say I overly enjoyed watching this animation. It caters to a certain audience, but I feel this animation could have been enjoyed more in some aspects.
The art style consists of firstly, sprites that you did not draw, and jpg's from the game as background images that you used the trace functions on. Firstly, correct me if I'm wrong but I'm reasonably certain Halo is not a game with 8-bit graphics, and I think I would appreciate more of the heart the animator put into this work if you attempted to draw the Halo guys, just like some other great Halo parodies on NG. Halo is a game of 3d graphics and the art style I feel doesn't really suit it. TRUE 'hard work' would be put in if you attempted to capture the aesthetic beauty of the halo models in the game. Using sprites for a game that (I'm pretty sure) does not have sprites feels like a shortcut, and original graphics would give you an individual voice or style in your animation.
Correct me if you disagree, but conceptually, the beauty in animation that I see is the soul of the author literally being poured into the drawings behind the work. I feel here there is basically only tweening, well-tweened in most areas, but I was baffled when in the line 'I love egyptian kings' the mouth looked a bit dodgy and the tweening in the rave party looked robotic.
Also, these 'bit' style characters seem completely out of place with the 3D rendering of the backgrounds... I'd suggest making 'bit'-style Halo backgrounds to fit the characters or hand-draw the dudes to fit the background a bit more.
I wish you could have drawn a lot more of this animation to capture an individual style, because with the same style of tracing and the same sprite sheet anyone could make a similar animation and you would not be able to distinguish any real original 'flair' or individuality here. Flash animation is about bringing things to life, but after watching what really is non-original graphics, tweens and traced backgrounds, I can't be too impressed with the visual aspects of the piece. You said you worked hard, but try pouring your heart and soul into an animation, try drawing everything.
Those aspects actually make me feel like the animation in this piece are minimal: only heads dodge, no lips need to move for the lip sync (this is the game of course), walking seems to be interchanging a couple of sprites and tweening quickly... it doesn't feel like Halo, and it would feel like Halo if you drew the guys yourself in a 2D style, made your own backgrounds... a cartoony Halo but something that fits the bill of what flash animation. Here, what we have feels never quite fitting and a bit out of place.
Did I feel entertained? I'm not too familiar with the song, but I would be a lot more entertained if I didn't have to look at some of the aspects I pointed out which don't quite give a very natural flow to the animation.
On the plus side, the use of special effects and sound effects were good. It's not a bad sprite movie, but I think the score compared to the 'greats' is almost insulting... is the animation magical and pleasing to the eye? Does it convey the complex emotions of the human condition? Or for humorous ones, is it well animated? Does it have a cartoon-like feel to emphasise the humour? Is the animator's ability used to the fullest capacity to convey the plot or elements of the narrative? Not really in this one minute video.
Is the beauty of the 'Halo World' captured in this video? I don't really think it can be with traced images and sprites, which feel out of place.