Mystery bonus symbol reveal

A method of controlling an electronic gaming device, the method comprising:

• determining which slot symbols will be presented on a display system of the electronic gaming device for an instance of a slot game, the symbols comprising one or more mystery symbols wherein each of the one or more mystery symbols is also a trigger symbol, and wherein the presentation of two or more mystery symbols corresponds to an award of a feature;
• controlling the display system to present first visual effects corresponding to the instance of the game, the first visual effects including moving symbols and landing of the one or more mystery symbols;
• controlling the display system to present second visual effects corresponding to the one or more mystery symbols, the second visual effects including a first mystery symbol revealing a first revealed mystery symbol image that corresponds to the first mystery symbol, wherein the first revealed mystery symbol image is also a trigger symbol and presenting both the first revealed mystery symbol image and the first mystery symbol together corresponds to the award of the feature;
• and
• controlling, based on presenting both the first revealed mystery symbol image and the one or more mystery symbols, the display system to present third visual effects corresponding to the feature.

One or more non-transitory media having software stored thereon, the software including instructions for performing a method of controlling an electronic gaming device, the method comprising:

• determining which slot symbols will be presented on a display system of the electronic gaming device for an instance of a slot game, the symbols comprising one or more mystery symbols wherein each of the one or more mystery symbols is also a trigger symbol, and wherein the presentation of two or more mystery symbols corresponds to an award of a feature;
• controlling the display system to present first visual effects corresponding to the instance of the game, the first visual effects including moving symbols and landing of the one or more mystery symbols;
• controlling the display system to present second visual effects corresponding to the one or more mystery symbols, the second visual effects including a first mystery symbol revealing a first revealed mystery symbol image that corresponds to the first mystery symbol, wherein the first revealed mystery symbol image is also a trigger symbol and presenting both the first revealed mystery symbol image and the first mystery symbol, together corresponds to the award of the feature;
• and
• controlling, based on presenting both the first revealed mystery symbol image and the one or more mystery symbols, the display system to present third visual effects corresponding to the feature.