Mysterious City: Vegas is a very basic hidden object game, following closely all the conventions of the genre. The owners of a Las Vegas casino hire a young female detective called Dr. Ellis to investigate a series of thefts and capture the culprit. Most of the time the objective is to search Las Vegas locations, represented as screens with little animation, to find and click on all the items listed at the sides of the screen. In some levels, the list displays the object's silhouettes instead of their names. The minimal plot is developed as comic book panels between each chapter.
The common variations are included, like the obligatory split-screen with two similar images, where the player has to click on the differences. The hint button highlights the position of one of the required items, but removes two minutes from the time left. The time limit can be selected at the start, between the default 45 minutes or the more generous 130 minutes of the relaxed mode.
The game has three mini-games that can be unlocked while playing, and later accessed and played through the main menu. The first is an implementation of poker, the second is a slot machine and the third is similar to Slingo, where the values on a 5x5 bingo card have to be matched with the random spinning numbers surrounding them.