Seriously impressive! It's been fun seeing the updates in the Flash Holes FB group.
My two suggestions would be:
-The train looks too 3D. Try and find a way to blend it in more naturally with the background
- In general, I'm sure these clips take a long long time, but I would say waiting till you have the bulk of it ready to go gives it more punch when you release it.
Seriously, though. Super, super impressive. How long do these shots take?