Hello, my name is Mike Gowen.

Learning Game Design: iPhone Gameplay and Engagement

I’ve been giving some thought to how my game designs would perform on various platforms, and how the typical usage model of a platform affects gameplay and potential engagement.

For example, playing a game on a home desktop computer affords very little inherent interruption of gameplay. You’re in a comfortable and stationary position; it’s easy to block out an uninterrupted session of play time; and assuming you’re plugged in, there are no power limitations that would affect the length of your session. This is the type of environment that a game like World of Warcraft thrives in, as it requires a fairly lengthy minimum amount of play time for a player to become fully engaged. In fact, it can take upwards of 20 minutes just to travel across the map.

Developing a game for the iPhone is a completely different animal. There are quite a few unique characteristics that will significantly affect engagement patterns, but we’ll stick to what I consider to be the two biggest factors: battery life and lifestyle. Let’s look at a hypothetical usage model of an average iPhone owner and how these factors dictate potential engagement.

Power

Let’s assume you have a player that religiously plugs in their iPhone 3G every night after a full day of unplugged, moderate to heavy usage. The absolute maximum playing time the player can achieve with your game is a function of the battery usage of your app divided by the total usage time of a full charge, which according to Apple is around 5 hours with all the bells and whistles enabled. If you’re game is power hungry and uses all the fancy schmancy features (Open GL, vibration, GPS, etc) by my rough calculations you may only see a maximum continuous play time of about an hour. Again, this is with a full charge.

Lifestyle

Being that an iPhone is a mobile device, usage will inherently be intermittent and based around the owner’s lifestyle. It is typically in it’s owner’s possession at all times and is used on an “as-needed” basis. A mobile device is destined to always play the role of a co-star…second priority to whatever it’s owner is doing at the time. In addition to competing with the everyday “goings on” of life, you also have to deal with competing application usage. The iPhone is not solely a gaming platform and will be used for many other tasks like browsing the web, checking email, getting directions, and countless others. The chances of a player draining their entire battery in a single playing session of your game is unlikely.

So what does this all mean to you as a designer? Well, the result of the above conclusions means you can expect the actual playing pattern to be a series of smaller fragmented playing sessions whose total equals the total potential play time on a full charge, minus the battery power used by competing applications. Wow, that was a mouthful. These playing sessions will probably be in the ballpark of about 2-10 minutes each. That’s just an estimate and will vary with each person, but you get the idea. This will have a significant affect on the short term engagement potential of your game. What are some ways to maximize this?

Well for starters, make sure you can be fully playing the game within a matter of seconds. As we’ve discovered above, time is precious. Don’t make your players go through numerous startup screens and menus before reaching actual playtime. Also, make sure the player can achieve gratification in smaller cycles. Rewards should be plentiful and come often. A game targeted for a desktop system with an average reward pace would fail on an iPhone as that pace would become mind-numbingly long broken up over a series of 2-10 minute sessions. Imagine traveling from end of the map to the other in World of Warcraft at that pace.

In summary, every platform is different and affords it’s own unique set of considerations. The iPhone and mobile devices as a whole are especially unique. When designing your game, be sure to always be conscious of the constraints and limitations of the platform with a goal of maximizing potential engagement within those confines.