Here is what I managed to figure out for the red boxes.
(Spoilers if you want to figure it out yourself)
1- They appear every ten chests and will have special music
2- If there is a timer on the side, you just have to check as if its a normal chest and try to get it before the timer runs out.
3- a secret will appear in the guide book, so check that.
4- Try clicking on the hinge a few times. If it makes a sound, keep clicking.
5- If there's an exclamation mark, a rocket will be shot and you just have to dodge it.
I'll add more if I discover something else.