GAME DEVICE

A game device of a computer game includes plural unit games, each of which can be completed when a requirement for completion is satisfied. The game device includes: a rule storage unit for storing rules of the computer game, in which the rules include rules stipulating the requirement for completion of each of the plural unit games and rules stipulating a content of play of each of the plural unit games; a difficulty changer for rewriting a rule stored in the rule storage unit so as to change a level of difficulty for completion of at least one unit game among the plural unit games; and a play processor for conducting a unit game selection process for enabling a player to select one from among the plural unit games, a play execution process for executing play of the selected unit game in accordance with the rule stipulating the content of play stored in the rule storage unit, and a decision process for deciding whether or not the unit game is completed on the basis of the rule stipulating the requirement for completion stored in the rule storage unit.