Designing for a Touch Screen
May 22nd, 2009
I play a lot of iPhone games; it’s part of my job (it’s rough, but someone’s got to do it). I’ve been thinking a lot lately about why some games feel so good to play and why others don’t. It wasn’t until I put my iPod touch down and picked up my PSP a couple of weeks ago that I started to formulate a hypothesis.
I hadn’t touched my PSP in about two years until recently. With the release of Patapon 2 on the PSN store (downloadable game store by Sony) for the PSP, I finally decided to plug it back in and charge up the long-dead battery.
Patapon is a rhythm game where you control little creatures on the screen entirely by sequences of button presses in time to a beat. For example, to make them move forward, you tap “square, square, square, circle” in time to the beat of the drum and they move forward a little. It’s fantastic and I’ve really been enjoying it.
Aside from enjoying the game, it also got me thinking about what I’ve been missing from the iPhone’s touch screen interface: buttons. This then got me thinking about why some games just feel right on the iPhone and others don’t.
Console video game systems all use control schemes that have physical buttons that you can press (with the exception of the DS, which has both buttons and a touch screen). The physical buttons are great because they provide tactile feedback to the player about where their fingers/thumbs are without having to look. When I’m playing Patapon, I don’t have to look at my right thumb because I know it’s on a button; I can feel the physical shape of the button. The iPhone, with its touch screen, is missing that tactile feedback.
However, what the touch screen excels at is providing a mental connection between touching the screen and something happening immediately below the point of touch. Where the touch screen excels is instances where you need to directly touch the object you want to interact with on the screen. Where it fails is when the touch point is separate from the result of the touch.
In other words, the touch screen is most effective when you’re touching where you’re looking. If you’re looking at point A on the screen, but the game requires you to touch something at point B, things break down. Because the touch screen can’t give you any tactile feedback that you’ve touched the right place, it feels sloppy and inaccurate.
Look at the games that have ranked the highest on the app store. Games like Flight Control or Pocket God require that you touch where you’re looking. In fact, you never touch the screen anywhere except where you’re looking. I think that’s part of the reason these games feel so intuitive and nice on the iPhone. The game is designed to be used the way the user expects the device to be used.
Conversely, many of the games that put on-screen controls onto the screen suffer from a clunky user experience. If you read reviews, games that have controls that substitute on-screen controls for a D-pad or buttons often end up being criticised for poor controls. If you think about an FPS on the iPhone, many of them adopt the technique of virtual analog sticks on the screen. But if you think about it, you’re looking at the centre of the screen where the bad guys are, so you can’t constantly look at where your thumbs are to make sure they’re still in the right place. The result is that there’s a disconnect between the controls and the game. Any barrier between the controls and the user enjoying the game results in a feeling of dissatisfaction.
There are exceptions to both of the examples I’ve given. However, my point is that as designers of iPhone games, learning how to effective use the interface we’re given is an important part of creating games that feel like they were meant for the device. By forcing control methods from button based controllers into our games, we’re not doing the player any favours. When you’re designing your next game, think not only of whether the game is a great idea, but think about whether it’s a great idea for the iPhone.
Owen
This entry was posted on Friday, May 22nd, 2009 at 10:06 am and is filed under Design, iPhone. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Great points, Owen. I particular agree with your comment that you should make the game fit the platform (this isn’t unique for the iPhone – some console games just shouldn’t be ported to the PC and vice versa).
I really liked the idea that designing with the touch-screen at the heart of your design, rather than trying to squeeze DS or PSP designs into a totally different beast, is the way to succeed.
Yep. Totally agree.
I’m trying to design an iPhone game, and actually I started thinking about the dynamics that I can achieve with touch control, instead trying to mimic something that works on a portable console.
One of the troubles of some games on the iPhone will be that you have to obscure your view when you touch the screen. Games that are FPS-style (first-person shooter) need to address the problem by not obscuring the screen with your touches (iSniper tries this). Other games might suffer if sufficient consideration isn’t given to the screen real estate.
The benefit of a PSP or DS is that the screen is somewhat independent of the controls. With the iPhone the screen is the control, so we need to be aware of this while making applications. Good thoughts, though! Thanks for the post.
I think you’re absolutely right, even if you’re stating the obvious (or what I feel *should* be obvious to every developer)
The fact that the screen is the control makes the device ill-suited for some genres and better suited for others. That also makes porting games from other platforms (be it console, mobile or pc/web) so hard and often failing. I think some developers fail to see how integral the control scheme of a game is to its design, especially if the design is reliant to fluid controlling of the avatar (as in pretty much every action game). Turn-based games tend to be more forgiving in this aspect, as you can switch your attention from the game space (i.e. the screen) to the controls and back. Also, as most turn-based games have some form of undo, the frustration created by accidentally making a wrong move is much lesser.
There have been some more or less successful implementations of controls “out of sight”, for example using the bottom of the screen as a horizontal slider to control a ship in a vertical shooter. As a rule of a thumb, I think games where you don’t directly control your avatar or tokens by tapping them, the controls should be pretty forgiving and relative. So instead of having a virtual control pad in the corner of the screen, calculate movement from the distance and direction of the moving finger, anywhere on the screen.
And the controls are not the only thing you should consider when developing for the iPhone, also the way the device is used is important. I’ve seen a lot of roleplaying games on the device that are huge and mimic their PC or console counterparts, failing not only due to the controls but also due to the different gaming environment. They demand longer gaming sessions and a lot of concentration, which is fine for a platform with which you sit down and dedicate time for, but with iPhone’s mobile nature, small screen, and limited battery power, the players tend to want shorter and more gameplay-intensive sessions.
As this is my first comment, thank you for the great blog, it has been a very informative read so far, since I’m also taking my first steps as an indie iPhone developer
This is an excellent post I will take it into consideration in my first app. It always seemed to me that the tactile feedback was super important in games.
I have been searching hard for info on this, so thanks for the post, any ideas where I can get more information?