iPhone Game Development - Chris Craft [28]
Trism is one of the first and most famous iPhone puzzle games.
Courtesy of Steve Demeter
Limit space
A good puzzle game can present challenges by requiring the player to navigate in a limited space. These types of challenges work really well on the iPhone because your screen real estate is limited to begin with. Instead of trying to work around this limitation, you will find you can compile games that leverage this limitation.
Here again, we can look at Tetris as a classic example of a challenge that is enhanced by making space a limiting factor. In Tetris, as the blocks pile to the top of the screen, the play area becomes very cramped and it becomes increasingly challenging to position the blocks without taking up even more space.
Consider some of the same key points when presenting challenges by limiting space:
Craft a clear and simple goal. You could provide the player with a target or exit, or you could have a puzzle that is only solved when all the pieces are oriented properly.
Carve a clear and easy path to the goal. Again, start with a simple, achievable goal. On early levels space may not even be a factor. However, it should be apparent that less space presents a challenge, which can actually add more enjoyment to the game.
Introduce obstacles. As the play progresses, you can start closing in the walls. Some of the same puzzles that players breezed through earlier become more difficult as the available space vanishes.
You have looked at three examples of presenting challenges, but by no means are these the only three. If you can invent a new way to present challenges, your game will stand out because it will be fresh and unique.
Embracing Multi-Touch
Multi-Touch is one of the many exciting features of the iPhone. You have probably played around with touchscreens before, but something about the experience created by the iPhone is new and unique. When your applications embrace Multi-Touch, you are delivering the experience iPhone owners have come to love (and expect).
When envisioning your game, try to think beyond buttons and joysticks and think in terms of interaction with your virtual environment. This is a bit more challenging than buttons because the interaction is no longer so cut and dry. The iPhone does not have a big red button to fire missiles. The relationship between input and response becomes fuzzier. This is a good thing! Input is now a rich and flexible world for you to leverage.
Leveraging a new style of input
Your goal should be to design a puzzle app with a user interface that delivers a more immersive experience than is possible with joysticks and keyboards. Multi-Touch opens the door to a new level of interaction that would be cumbersome otherwise. Think about dealing with keyboard input on joystick-based games. How many times have you had to enter your initials or name in a game where you had to scroll through the alphabet to select each character? The iPhone simply scrolls a virtual keyboard on the screen, allowing you to quickly enter the characters with minimal keystrokes. The AmuckSlider game we discuss later in this chapter greatly benefits from Multi-Touch (Figure 3.4).
In a real slider puzzle game, you physically slide the tiles from where they are to an adjacent empty cell (Figure 3.5). To truly embrace Multi-Touch, you need to create a virtual experience as close to the physical sensation as possible. AmuckSlider accomplishes this by requiring players to mimic the same physical gestures that they would use on a real puzzle.
FIGURE 3.4
AmuckSlider in action
FIGURE 3.5
A traditional sliding puzzle game
Learning the technology
The examples on the Apple development portal are great! If you have not done so already, we highly recommend that you peruse the plethora of example apps available there. At the time of this writing you could find an example there called MoveMe (http://developerapplecom/MoveMe), which is a great introduction to Multi-Touch. This simple application has a placard on the screen that you can grab and drag with your finger (Figure