This video (1:52) shows a reenactment of Naumachia, staged naval battles which were very popular in the Coliseum in Rome. Archaeologists have found marks at the bottom of the ancient Shuni remains suggesting the site was probably used, among other things, for military water games such as these during the Roman period as well.
In the Coliseum, Naumachia battles would combine large dummy ships and simulate historical battles for mass entertainment purposes. However, these show fights were not « games », but real fights between fighters, many of whom were wounded and some even killed there. Shuni is much smaller than the Roman Coliseum, with no room to bring in such massive ships, so the show-fights would of course have been smaller in scale.