You hold a note better than I ever could
I love your voice! I also think the sudden key change really works well with this song. I don't know if you intended for it to sound so sudden, but it really adds to the emotion of the second half.
Is it just me, or is the timing very slightly off at 0:57 and between 1:52 and 1:56? If so, you could probably fix it if you load the individual tracks into Audacity or suchlike. Also, the clicks at 2:27 and 2:28 are very regrettable, as is the fuzziness just afterwards. Remember to check all your tracks for volume clipping all the way through.
Despite those two points, this is more than good enough to be used in Flash movies (and that's what we're all here for, after all) and I hope that it gets used in many!