OpenTTD is a clone of the Microprose game "Transport Tycoon Deluxe,"
a popular game originally written by Chris Sawyer.  Significant
enhancements from the original game include bigger maps, new AI,
stable multiplayer mode, dedicated server mode, and many in-game
updates.

Historically, users of OpenTTD needed access to several original
Windows data files in order to successfully run the game.  However,
now there are two options:

1.  Using open source data files.

There are now open source equivalent files for the graphics (opengfx),
sound (opensfx), and music (openmsx) data files.  This script includes
support for these three extra downloads and will move the files into
the right place so long as OPENDATA=YES (which is the default).

2.  Using the original Windows data files.

Alternatively, the user can still use the original Windows data files.
If the original Windows data files are going to be used, then they
must be copied into the /usr/share/games/openttd/data directory before
the game can be played.  List of the required files: sample.cat
trg1r.grf trgcr.grf trghr.grf trgir.grf trgtr.grf.  Note that the
user can either set OPENDATA=NO in which case the open source data
files will not be used by the script and OpenTTD.  Or, the user can
keep OPENDATA=YES in which case the open source data files will be
included giving the user the ability to choose which data file set
(original Windows or open source data files) to use within the game
options menu.