Intel UMPC User Manual

Best Practices
in Game Design for
the Ultra-Mobile PC

by Matt Gillespie, Michael Finkel
and Victoria Bailey

The Ultra-Mobile PC (UMPC) will expand the market for PC games that run
on Microsoft Windows* XP, as long as developers consider certain design
requirements to ensure a good user experience. In most cases, a single
version of games can span both the UMPC and traditi onal PC platforms.

1 Introduction

The Ultra-Mobile PC (UMPC) platform is of increasing importance as a target
system for game developers. Because these systems run on Micro soft Windows*
XP Tablet PC Edition, they don't require a full operating system port for existing
games, but the UMPC form factor does i ntroduce a number of unique
considerations in game design. For example, UMPCs typically hav e a touch
screen with 800x480 or 1024x6 00 resolutions, which are small pixel si zes and
unusual aspect ratios. Developers must al so accommodate alternatives to
conventional keyboard and mouse user interaction, and a CD-ROM drive is
typically not available.

The best practices in this document for enabling PC games to run successfully on
the UMPC platform are based on an analysis of a large number of PC gam es
currently on the market. Those g ames were executed on a UMPC to identify
common strengths and weaknesses as sociated with the platform, as well as
specific game-design factors tha t contribute to the best user experience. Th e
analysis includes design considerations for providing high-quality games on the
UMPC, as well as common issues associated with providing UMPC support,
providing best practices to resolve each of those issues.

2 Screen-Size Considerations

Because the UMPC screen is much smaller than a traditional screen, the size of
graphical elements must be handled with some care. Developers must avoid
making scaled-down graphical el ements too small, as well as allowi ng elements
that are left the same physical size to consume too much screen space.
Specifically, text and icons are of ten hard to see clearly, some buttons or units
are difficult to click reliably, and some game windows do not fit entirely onto
the screen.

2.1 Text and Icon Sizes

Issue: In the interfaces of games that are ported to the U MPC, text or icons
may shrink to a size where it become s difficult to see them clearly. This
prevalent issue is important to avoid, because text and icons become useless if
they cannot be read or differenti ated. Text that appears reasonably sized on a
15” screen can easily become too small when shrunk to a five- to seven-inch
screen that you might find on a UMPC. Aside from the actual font size of tex t,
chat and other text windows may become too small. Accommodating smaller
window sizes by decreasing the f ont size can make the text difficult to re ad.

Best Practice: Ideally, game s designed with the UMPC in mind shoul d use text
sparingly and consider the UMPC scr een size when choosing a font. Likewis e,
icons should not rely heavily on fine details, so different objects are diff erent
enough to be easily distinguished from one another, even on the smaller UMPC
screen. In places where increasi ng text size enough would compr omise other
elements of the game, allowi ng text size to be adjustable may be a good
solution, allowing individual players to decide for themselves the ideal size for
the text.

2.2 Clickability of Buttons and Other Elements

Issue: Similar to the issue of smal l text, buttons and other clickable game
elements add complexity to porting games to the UMPC. Tha t is, while the
overall interface on the UMPC must be smaller than the corresponding standard
PC version, the actual buttons in the UMPC i nterface must be larger, in order to
accommodate being accurately clicked by a stylus or finger, rather than the
more precise mouse that is used in the standard PC version. As shown in Figure
1, this issue is particularly acute when multiple buttons or other elements are
clustered together, which makes it more likely that the user will select a
different element than the on e they intend. Even when it is po ssible to select
the correct element with som e care, this issue can significantl y detract from the
user experience.

Figure 1. On a 20-inch PC monitor (left), the user can easily identify and select a domino
using the arrow cursor. When the domino images are scaled to fit on a five-inch UMPC
screen (right), however, it becomes very difficult for users to select individual dominoes, or
even to identify how many dots are on each domino.

Best Practice: As with the size of t ext and icons, game developers should avoi d
this problem by using larg e, distinct buttons and other elements. These
elements should also have enoug h space between them, making it less li kely
that the user will inadvertently select the wrong one. In those cases where a
text label appears adjacent to a button or other element, that label should be
part of the clickable area as sociated with the element, making it easier to click
without having to devote any additional sp ace.