Arduino 16x2 LCD cookie clicker which uses four buttons to control the game.
SELECT: Click the cookie/buy an upgrade
LEFT: Open/close upgrade menu
UP: Navigate up in the upgrade menu
DOWN: Navigate down in the upgrade menu
Easy to expand and rebalance, uses preprocessor directives and globals to define the game's variables.
Built as a proof of concept, but can be expanded to a full game (overflow handling, nicer menus, off-screen handling etc).