Let's make a coin collection game. Here, the player should control a character in the first-person mode, and he must wander the level, collecting all coins before a time limit runs out. If the timer runs out, the game is lost. On the other hand, if all coins are collected before the timer expires, the game is won. The first-person controls will use the default WASD keyboard setup, where W moves forward, A and S move left and right, and D walks backward. Head movement is controlled using the mouse, and coins are collected by simply walking into them. See Figure 1.1, featuring the coin collection game in action in the Unity Editor.

The great benefit in making this game is that it demonstrates all the core Unity features together and we don't need to rely on any external software to make assets, such as textures, meshes, and materials:

Figure 1.1: Preparing for a coin collection game (the completed game)