good to actually see some vfx here.
the modeling is decent here, but i'll can touch on a few things.
first, the grading. while i do agree that it needed a bit of work when transitioning, i feel that going static doesn't really help it any. maybe next time find a palette you like of 4-5 colors and swap between them whenever switching scenes. that way you can have a gradients that are fitting without having the whole movie feel blurred together. because when you switch settings, you wouldn't expect the environment to feel the exact same as the other, especially a switch as drastic as going from space to a city. so i while agree with your professor that the original didn't match too well, it looks a lot better than having the whole movie match.
also, the re-submission is a bit dim, i'd maybe bump up the brightness a touch.
you did a good job masking, but this really stuck out to me:
while i see how this can happen when using particle system, the way the tie fighters come out is still a bit too uniform for me. if it's supposed to be this giant warp, i don't really buy the fact that they're only coming through 3 areas of it.
i'm sure that you noticed that the tie fighters are colliding with each other, so i'm sure you know that it needs a bit of work. but you mentioned a deadline, so i get it.
also, when the tie fighters spawn in from the warp they're a bit bugged. it's only for like a frame or two, but it's still very noticeable. i'd duplicate the warp, mask it out where you want the fighters to come in, and add a soft mask. it should create a discount "fade in" effect if you will. seeing as you can't just change the opacity for the entry without affecting the entire fleet.
the guy just standing there while the fighters are coming in is a bit.. distracting. doesn't really feel like a natural reaction. especially if it as you've titled, an "invasion", the dude seems pretty fine with it.
the last thing i'll touch on as far as visuals go would be to add some motion to the scenes. it all feels too still. like in the tie fighter for instance, it doesn't seem like it's moving any. and because of that loses the effect of travel, making it look a bit dull. maybe move the image of space a bit in the start of it. the same applies for the scene of the city, maybe a bit of camera shake would add a more genuine effect.
also, a small touch on audio.
there is a whole lot of clipping going on. the next time you go to introduce a clip of audio, or go and separate pieces of audio, always be sure to put a small fade in/out on each clip. i'm talking maybe 0.08 of a second long, or something very short. without it you are left with these audible clicks whenever you introduce each piece of audio.