Create an image of a fantastical underwater city hosting a vibrant cultural festival, where mermaids and sea creatures come together to play a thrilling game of underwater charades.

Visualize a captivating underwater city in a fantasy world, where luminescent buildings of coral and intertwined seaweed shimmer in the watery depths. The environment is alive with a vibrant cultural festival, exuding an ambient radiance. Mermaids of diverse descents, including Black, Hispanic, Middle-Eastern, and South Asian, are co-mingling with a variety of colorful, fantastical sea creatures. They are all eagerly participating in a thrilling game of underwater charades, their unique gestures creating a dance-like spectacle against the backdrop of the city’s captivating beauty.