These "slice of life", realist drama-comedies are far from my favorite genre, but as a serious movie buff, I've seen tens of them over the years, and Standing Still is right up there with the best of them.
The only flaw I can find, really, is the title, which is a bit enigmatic (not that I mind enigmas, but it's a bit out of context here). A better title would have been "Secrets", or even "Shuffle" if something less obvious was desired, as the plot is focused on an event--a wedding--that brings a wide range of people together, some unexpected, almost all with some kind of secret, and reshuffles them in various ways--often through revelations of their secrets.
Realist movies can easily become unfocused or boring--after all, that's true of most folks' lives if we were to follow them around with a video camera and expect people who don't know them to be entertained watching the results. But Standing Still manages to create suspense, tension and a healthy dose of humor while expertly weaving together a large number of threads, all while keeping things fairly firmly in realist territory and providing satisfactory resolutions. It's also emotionally satisfying and relatively "deep", often in subtle ways, all aided by the fantastic performances. Everyone says just as much with subtle body language as they do via their dialogue, and this just as often occurs in what could tend to be read as the lighter or shallower scenes.
I wanted to see far more about every one of these characters--and we could hardly call that a flaw.