Engaging intro - then kinda disappoints.
Those choral parts in the beginning were really nice and smooth, and the chords they projected have a certain emotional impact (though I kept waiting for that suspension/dissonance to fall, which never happened :P).
The next parts were really drab by comparison, especially the piano - having it repeat the drum rhythm felt unnecessary and rather stiff and awkward (due to the lack of velocity variation). As for "dominat[ing]" 5/4, it does sound fairly smooth melodically, but the actual rhythmic pattern itself is pretty dry and boring (ie, try throwing in some "kinks", such as 2/4 + 3/4 rhythms and 4/4 + 1/4 and such, as well as adding some more complexity to the drum parts itself).
The ending was unexpectely neat though - those sirens were a really nice touch for sure. But I'd hold that last chord a bit longer and let it simmer down slowly in silence for added effect, while the siren repeats again fading out moreso.