Talking Towers

01/02/2010 by John Daud

Talking Towers

Greetings!  My name is John Daud and I'm a designer at Hidden Path
Entertainment.  Our latest project is a tower defense game called
Defense Grid: The Awakening.  Our goal for this title was to take all of
the fun we were having playing web browser tower defense games and add
some production value to the genre through complex sound design,
gorgeous art and a compelling story.

Defense Grid was principally inspired by the imagination of our CTO and
one of the company founders, Michael Austin.  Michael had played a
number of tower defense games and was fascinated by the game mechanic,
but believed that there was great opportunity for improvement in
graphical fidelity and game play.  He discussed his idea with Mark
Terrano, another founder and our Design Director.  Mark bought into
Michael's vision and assembled a proposal.  From there, the principals
generated a great design document that set the product tone.

But the design contribution went far beyond Michael and Mark.  Design at
Hidden Path is a truly collaborative effort that involves everyone on
staff.  Every member of the team has a wealth of game development
experience and a broad knowledge of many game styles.  Consequently, the
team considers all ideas and suggestions, regardless of whether the
source is an artist, a programmer or a designer.  With such a strong
group working on the title it was no surprise that in a matter of months
we were already playing a fun, addicting and great looking prototype
level.  After we agreed on what made the game fun, we just needed more
content.  So my primary role on the project was to design and build many
new levels, leveraging off of that initial prototype.

To construct level maps, we used a proprietary map editor built
specifically for this title. The tool allowed me as a level designer to
either construct constrained paths, open platforms or combinations of
both.  In tower defense games, the antagonist comes into the map messes
up your world (in our our case they steal precious Power Cores) and
leaves, either from the point of entry or a separate exit.  So we knew
we needed spawn points, exit points, and power core positions defined in
the editor.  One of the most exciting features of our map editor tool
is the procedurally generated geometry.  The constrained paths - where
the landscape of the environment determines where the enemies can move -
are defined by series of connected waypoints.  These automatically
generate the path geometry complete with the path surface, guard rail,
lights, support structure, pipes, etc.  This technology also allows
sections of the map that are designated buildable areas to be
procedurally generated with the sci-fi industrial design appearance we
wanted.  With the game play-specific elements procedurally created, the
artists can focus on geometry in the levels that really brings the
environment to life and truly takes the Defense Grid aesthetic to a high
level.  One of the coolest parts of the process was seeing what the
artists created out of my collection of paths and tower platforms. 

Of course, making each level fun and unique was a critical part of my
job. I had many different variables to play with to accomplish this. One
of the cool things about tower defense game design is the ability to
"tweak the knobs" in order to adjust the game play experience: the
number of enemies attacking, the time between waves, the type and
strength of the invaders versus the types of towers at the player's
disposal, how many resources the player has at the start in order to
build those towers, the number of spaces available to build in... all of
these variables can be adjusted to subtly or radically change the
player experience.  And while surviving a Defense Grid level is
certainly fun, another effect of these many variables is the desire to
replay the level in order to achieve a better score or a higher medal
value.  "Did I need to build that last tower?" "What if I frontload my
defenses instead of building near my cores?"  "Maybe the Inferno tower
would be more effective than the Laser in that one build spot..."  "How
did that guy finish the mission with 800 more resources than me?"  As a
level designer, I want to know the ideal strategy for any particular
mission, and I want to provide the player with a challenge while they
search for the perfect defense. Personally, it is great to hear about
someone waking up after playing our game the night before with an
inspiration for a better defensive strategy for some particular mission
in our game.     

I am thrilled that even after all of the months of hard work put into
this game that the development team still can't stop playing the thing. 
I can honestly say that I had a great time working on this game, and I
am very proud of Defense Grid.  I hope you share my excitement, and that
this diary adds to your appreciation of the game.  See you on the
leader boards!

Posted in Defense Grid | Keywords: Defense Grid