Tried too hard to be more than it was
It tries to balance being hip, a romantic comedy, a thriller, a who-done-it, and introspective. There isn't enough there to hold it all together. It starts strong, has a slow middle, and the last 30 minutes feel rushed and IMO unbelievable.
The rest of the cast is pretty cookie-cutter, but Glen Powell does carry this thing on his back and its easy to see why he's the new hot guy in Hollywood. Reminds me of Bradley Cooper when he shot to fame.