Do you mean 'export LANG=en.UTF-8;ufo' ?
Because setting LANG env. changed my locale to english (in the output of locale program), but the game worked the same way: English cannot be selected only No language and Hungarian.
There is no need export LANG. Setting it (more precisely LC_MESSAGES) for ufo process is enough. I can see and switch to a different languages, but if I don't set LANG to appropriate locale, I still don't see the messages.
$uname -rs
FreeBSD 6.3-RELEASE
$echo $LANG
uk_UA.UTF-8
$pkg_info -L ufoai-2.2
Information for ufoai-2.2:
Files:
/usr/local/bin/ufo
/usr/local/bin/ufoded
/usr/local/bin/ufo2map
/usr/local/lib/ufoai/base/game.so
/usr/local/lib/ufoai/base/i18n/cs/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/da/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/de/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/en/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/es/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/es_ES/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/est/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/fi/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/fr/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/ja/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/it/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/pl/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/pt_BR/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/ru/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/slo/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/sv/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/base/i18n/th/LC_MESSAGES/ufoai.mo
/usr/local/lib/ufoai/ufo
/usr/local/lib/ufoai/ufoded
/usr/local/lib/ufoai/ufo2map
/usr/local/lib/ufoai/base/autoexec.cfg
/usr/local/lib/ufoai/base/dedicated.cfg
/usr/local/lib/ufoai/base/default.cfg
/usr/local/lib/ufoai/base/keys.cfg
/usr/local/lib/ufoai/base/maps
/usr/local/lib/ufoai/base/media
/usr/local/lib/ufoai/base/models
/usr/local/lib/ufoai/base/music
/usr/local/lib/ufoai/base/pics
/usr/local/lib/ufoai/base/shaders
/usr/local/lib/ufoai/base/sound
/usr/local/lib/ufoai/base/textures
/usr/local/lib/ufoai/base/ufos