Kevin Costner‘s new Western epic may have gotten a 10-minute standing ovation at Cannes, but once critics got back from festival screenings to their hotel rooms, they posted reviews for Horizon: An American Saga — Chapter 1 that were far less enthusiastic.

Horizon is the first film in writer-director-star Costner’s massive four-picture gamble which he famously leveraged one of his homes to help finance (spending $20 million out of pocket for the $90 million-budgeted film). Chapter 1 is three hours and is largely focused on setting the stage — introducing a sprawling ensemble of characters, with the promise of more dramatic events to come in the remaining films.

There are not a large number of…