Game Development Reference
Figure 2-1: Tap Zoo, 2011's top-grossing iOS game
Short, Discrete Gameplay Sessions
Here's the thing about the iOS: For the most part, it's still mainly a mobile phone. Which means an iOS game
is often (or usually) played in contexts where a mobile device comes in handy most: in remote locations away
from the living room or office, during idle times. (Say, waiting for a bus, traveling on a plane and, yes, sitting
in a bathroom.) For that reason, the iOS is better suited to games with short, discrete gameplay sessions that the
player can easily quit and return to at any given time. To take an iconic case, a complete Angry Birds level can
be played in less than a minute, but typically takes several minutes. This is a good time frame to aim for.
2D or 2.5D Games
While many 2.5D games may appear to be 3D, using an isometric perspective, camera control over the game scene is severely limited. Hence
the term 2.5D.
Another common feature in top-selling iOS games is 2D or 2.5D graphics, where gameplay is depicted on a
flat, single-plane surface, or in a 3D space limited to a single perspective . This is probably due in part to the
comparable difficulty of playing a 3D game on the flat surface of an iOS (see the section “Full 3D Games”) and
iOS touchscreen interface (see “Games That Leverage iOS's Touch Interface”), which works much better with
2D/2.5 gameplay, because touch literally connects the player to the screen.
What Doesn't Work on iOS
Now that you know what works best on iOS, take a look at what doesn't work so well.