1. A game device comprising: a display screen; at least one storage device that comprises at least one memory; at least one software component stored in the at least one memory; and at least one processor, when reading and executing the at least one software component, configured to at least: a) control progression of a game having at least a non-battle mode and a battle mode in which a player character of a player battles an enemy character; b) decide stop positions of spinning slot reels of a first reel group in the battle mode; c) select a type of battle action among plural types of battle action of the game in the battle mode, with reference to the stop positions of the spinning slot reels of the first reel group decided, each of the plural types of battle action having an attribution associated with a set of symbols of the slot reels of the first reel group at the stop positions, the plural types of battle action including a first type of battle action having a first attribution to attack the enemy character and a second type of battle action having a second attribution different from the first attribution; d) decide the selected type of battle action as a battle action by the player character in the battle mode; e) decrease hit points of the enemy character in response to the battle action by the player character in the battle mode; f) decrease hit points of the player character in response to a battle action by the enemy character in the battle mode; g) determine a winner based on respective remaining amounts of the hit points of the player character and the enemy character in the battle mode; h) accumulate parameter values associated with the symbols at the stop positions each time the spinning of the slot reels are stopped in the battle mode; i) recognize whether an accumulated total value of the parameter values exceeds a reference value in the battle mode; j) select a different type of battle action when the accumulated total value exceeds the reference value in the battle mode, wherein the different type of battle action is different from any available types of battle action which are selectable when the accumulated total value does not exceed the reference value; k) display, in a first display mode, a non-battle image of the game in the non-battle mode on the display screen without displaying the slot reels on the display screen, wherein the non-battle image does not depict a picture of the enemy character; l) display, in a second display mode on the display screen, the slot reels together with a battle image of the selected type of battle action simultaneously in the battle mode on the display screen, without displaying the non-battle image of the game in the battle mode in the first display mode on the display screen; m) display, in a third display mode on the display screen, a plurality of group symbols indicating a plurality of player groups to allow the player to select a group symbol from the plurality of group symbols to designate a player group, indicated by the selected symbol, to which the player will belong; n) generate an operation information that indicates the group of which group symbol the player selected; o) update a status of the game progression based on the operation information; p) display, in a fourth display mode on the display screen, a plurality of play region symbols indicating a plurality of play regions to allow the player to select a play region symbol from the plurality of play region symbols to designate a play region, indicated by the selected play region symbol, in which the player will play; and q) in response to having selected a play region symbol, display, in the first display mode on the display screen, the non-battle image.