The last act is pretty great, but everything up to that is just so messy. It tries to balance an epic story with a convoluted plot (which basically boils down to a 'ticking time bomb'), whilst awkwardly attempting a 'time passing' segment that flat out doesn't work.

Also the action really is terrible, poorly staged with no attention to composition or geography. Nolan wants too much to paint on a broad canvas, and forgets that to make that work he must pay attention to the detail.