Given the constraints and the era of the device, let's design a simple yet engaging feature for a game like "Treasure Quest," a puzzle-adventure game. Game Overview: Treasure Quest is a puzzle-adventure game where players navigate through increasingly challenging levels to find hidden treasures. The game is designed to utilize the N-Gage's unique features, such as its keypad for input and the ability to play in both landscape and portrait modes. Feature: "Power-Up Portal" Description: A new power-up that temporarily reveals hidden paths or secret areas within levels, encouraging exploration and replayability.