Kevin Costner put $20 million of his own cash behind 'Horizon: An American Saga — Chapter 1.' Critics say it sucks.

Kevin Costner at the Cannes Film Festival 2024 and in "Horizon: An American Saga — Chapter 1"Pascal Le Segretain / Getty Images / Warner Bros

• Kevin Costner's new movie "Horizon: An American Saga — Chapter 1" premiered at the Cannes Film Festival.
• Costner left "Yellowstone" and spent $20 million of his own money to make the movie.

Kevin Costner's upcoming western movie, "Horizon: An American Saga — Chapter 1," which he mortgaged a house to fund, was battered by critics after its premiere at the Cannes film festival.

Costner has invested a lot in "Horizon," a four-part movie the actor-director has been trying to make since 1988.

According to The Hollywood Reporter, Costner paid $20 million of the total $90 million-plus budget for the movie series, and mortgaged his seaside estate in Santa Barbara, California, to fund it.

Last year, Costner also testified in court during a child-support hearing that his sudden departure from "Yellowstone" in 2023 was influenced by "Horizon."

Costner directs, stars in, and cowrote "Horizon," where the first part premiered at the Cannes Film Festival on Sunday.

(The second part is also ready for release soon, while the rest are still in production.)

However, critics were not impressed, and the movie's Rotten Tomatoes score currently stands at 20%.

Here's what critics have said about "Horizon: An American Saga — chapter 1," which premieres in theaters on June 28.