My god, that was AWFUL. Just random made-for-trailer tiny scenes that add to nothing, have zero depth and don't make up a coherent plot. Wall-to-wall inappropriate songs that come at random times. Boring plot (if you can even call it that), boring and indistinguishable flat characters. Harley Quinn was annoying. Jared Leto did his best as The Joker but had absolutely nothing to work with - he just appears at random times for a few seconds and disappears. There's no depth and no story. If you've seen the trailers, you basically saw all the one-liners and "money shots".
If all that isn't enough, the last third of the movie is simply unwatchable.
I don't think David Ayer is a bad director (I liked HARSH TIMES and FURY), but this is definitely his worst movie yet and I'm pretty sure it's due to massive pressure from the producers.