More Movement (Basic AI)
Most casual games involve a player and some form of computer AI (Artificial Intelligence). Basically an AI object will interact with what’s onscreen and what the player does. For example, in a top-down game the AI object may move toward the player avoiding other objects and shoot a bullet toward the player if they’re within a certain range. Usually in the first few levels of a game the AI object will be more forgiving to the player, but higher levels may make the AI more aggressive.