Bonus items
Now let's focus on a distinct and extensible feature, namely bonuses or rewards. Rewards systems and positive feedback are important properties for games wherever the player repeatedly encounters time-critical challenges. When provided judiciously and appropriately, rewards reinforce the player's successes, making them feel good, and encouraging them to play on. It's important not to over or under-reward. By under-rewarding, you make the game seem too difficult or boring, and by over-rewarding, you remove the challenge and desensitize the player to rewards completely.
Rewards take many forms, from steam achievements, certificates, and badges, to power-ups and extra items. For more information on player motivation and in-game achievements, see the book Gamification with Unity 5.x, Packt (https://www.packtpub.com/game-development/gamification-unity-5x). In Dead Keys, we'll reward the player with collectible badges. These are issued based on typing time: that is, when the player...