UFO: Alien Invasion
https://ufoai.org/ Formula was removed
Last versions were

Revision: 2

ufoai requires the following formulae to be installed:
pkg-config 0.29.2 Manage compile and link flags for libraries
sdl2 2.0.8 Low-level access to audio, keyboard, mouse, joystick, and graphics
sdl2_ttf 2.0.14 Library for using TrueType fonts in SDL applications
sdl2_mixer 2.0.2_3 Sample multi-channel audio mixer library
jpeg 9c Image manipulation library
libpng 1.6.34 Library for manipulating PNG images
xvid 1.3.5 High-performance, high-quality MPEG-4 video library
theora 1.1.1 Open video compression format
gettext GNU internationalization (i18n) and localization (l10n) library

Recent formula history

FX Coudert ufoai: remove
ilovezfs Use “squiggly” heredocs.
ilovezfs ufoai: revision for jpeg
Viktor Szakats ufoai: secure url(s)
JCount ufoai: update sdl2_mixer dependency

Formula code at GitHub