Mini games occur frequently in Riviera: The Promised Land. Many chests and events require that one successfully win these games in order to reap the reward. Often, the player is penalized in various ways if they fail, with no second chances or retries. When a mini game begins, the main game goes still and fades away a bit as the game flashes twice on screen and begins immediately; one must be ready. Most of these games will immediately end once the player messes them up.
There are various types of mini games in Riviera, the most common of them being one that involves pressing the series of buttons on screen within very limited time; the time varies and can often be very short or long depending on the event.
In another one, a bar appears, with a small portion of it being filled in. An icon will quickly glide along it back and forth, and the player must stop it (press A/X) only on the highlighted area, or else the game will be considered a failure. The size of the "sweet spot" can vary from lenient to precise (very small).
Another game involves a line of button commands, each of them must be pressed as the cursor passes by on the bar beneath them. Pressing the wrong button or pressing a button when there is nothing above the cursor is a negative mark, and a single one makes the game a failure. This one does not end immediately upon a screw up. The difficulty of it varies with the event in question.
Next is another common one, and one that cannot be lost. A roulette of items will rapidly alternate on screen, and pressing A/X will halt it, which will be the item you will get. A test of luck! This one is encountered only when a chest is opened, and the available items depend on the stage.
Lastly, and perhaps the simplest, is to repeatedly tap the button specified on screen a number of times within the alotted time. Like always, the time and amount varies per event. If time runs out, or when the button is pressed enough, the game is over.