Update to 1.4.
From the release notes:
| For players, the 1.4 version brings you no fewer than seven new
| mainline campaigns, a redesigned user interface, an amazing variety
| of high-quality new game music, and a refresh of the game artwork
| including improved portrait images for many unit types. For
| designers, the map editor and WML have been enhanced to
| significantly increase your creative options in writing scenarios.
See also: http://www.wesnoth.org/start/1.4/