Collateral

They filmed a great movie, and then diluted it into a so-so generic summer flick with unnecessary elements and characters.

Vincent and Max create a unique conflict and a very interesting dynamic. The acting is excellent and really sells the characters idiosyncrasies.

However, the trope of the one cop who cares and tries to figure out what ia going on is not only a tired cliche but it was also poorly shoehorned into the film. The cop's motivations and character are not developed at all, and it feels artificial, because we know he only exists to advance the police angle, which itself is unnecessary and only inserted to fill a Hollywood need for perfectly resolved ending.

Then the whole police angle is abruptly dropped and we never see them again.

Half way through the film, the tension is completely abandoned and replaced with a fast paced action flick. After a flashy shootout violence loses its realistic punch, the dark tone can't be recovered.

The ending was also weak and generic.

They shot a great film, but decided to hedge their bets by adding a summer blockbuster action flick on top of it. The result is a disappointing movie that really seems like three films stitched together, the original film, the cop film, and the action flick at the end. Collateral would have been great if it had modicum of artistic courage.