The movie draws inspiration from the true story of Benjamin Siegel, known as “Bugsy” (played by Warren Beatty), charting his transformation from a petty criminal and womanizer into someone with ambitions in property development during the early days of Las Vegas, coinciding with the construction of the Hoover Dam and its availability of inexpensive power. Throughout this journey, he abandons his family while becoming infatuated with aspiring actress Virginia Hill (Annette Bening), whose tolerance for his actions is quickly strained by his carefree nature and a tendency to court danger. The situation escalates when he suggests to Meyer Lansky (Ben Kingsley), essentially his financial backer, that they invest $2 million in constructing the Flamingo – a modern resort and casino intended to make them all wealthy. However, expenses rapidly exceed expectations, leading his superiors to view him as more of a burden than an advantage. Reports suggest “Bugsy” was a ruthless man who showed no mercy, but Beatty doesn’t quite manage to portray that aspect effectively, and his performance diminishes as the film progresses. Bening's character also feels underdeveloped, with limited opportunities for her to make a significant impact beyond some initial allure and occasional outbursts. While there is an undeniable connection between them, it isn’t frequently showcased, contributing to the film's overall feeling of detachment. I wasn't bothered by the numerous alterations to ages, descriptions, and origins that were clearly taken for artistic license; however, I struggled to believe any of it could have actually happened. It's visually appealing, without a doubt, but ultimately lacks substance – unfortunately.

Source on TMDB