Game of chance with short- and long-term persistence features

An electronic gaming system comprising:

• one or more displays;
• and
• a game controller that includes one or more processors and one or more memory devices, wherein:
• the one or more processors, the one or more memory devices, and the one or more displays are operably connected, and
• the one or more memory devices store computer-executable instructions which, when executed by the one or more processors, cause the one or more processors to:
• a) cause a graphical user interface (GUI) for a first game of chance to be rendered via the one or more displays, wherein the GUI for the first game of chance includes a plurality of symbol positions and has an activatable feature game mode;
• b) cause a plurality of scatter prize indicators to be displayed by the one or more displays via the GUI for the first game of chance, each scatter prize indicator associated with a different one of the symbol positions and selected from a plurality of tiers of scatter prize indicators;
• c) cause, responsive to each receipt of a player input signal indicating a play of the first game of chance while the feature game mode is not activated:
• d) a plurality of symbols to be selected and displayed in a different one of the symbol positions in the GUI for the first game of chance;
• e) the GUI to display the scatter prize indicator or indicators that is or are associated with any of the symbol positions that is or are associated with a selected symbol or selected symbols that is or are a first type of symbol and that meets or meet a scatter prize indicator upgrade condition being upgraded to the next higher tier of scatter prize indicators;
• and
• f) the GUI to initiate an instance of the feature game mode responsive to the GUI displaying at least a threshold number of symbols that are the first type of symbol responsive to the receipt of the player input signal indicating the play of the first game of chance wherein the one or more memory devices further store additional computer-executable instructions which, when executed by the one or more processors, further cause the one or more processors to, responsive to each receipt of the player input signal indicating a play of the first game of chance while the instance of the feature game mode is ongoing, cause:
• g) a symbol to be selected and displayed in each symbol position of the GUI that is in a first set of the symbol positions that at least excludes symbol positions that previously displayed a symbol of the first type of symbol during a current round of that instance of the feature game mode,
• h) a play counter displayed in the GUI for that instance of the feature game mode to be reset to a default number of units when at least one symbol selected and displayed in one of the symbol positions of the GUI in (g) is the first type of symbol and to be changed by one unit when no symbol selected and displayed in the symbol position or symbol positions of the GUI in (g) is the first type of symbol, and
• i) the GUI to indicate that that instance of the feature game mode has concluded when the play counter reaches a predetermined value.