Tyrian is a vertical scrolling shooter. The game takes place in the year 20,031. The game first follows a skilled terraformation pilot named Trent Hawkins as he tries to escape from a corporation named Microsol. Microsol wants to kill Trent due to his knowledge of Gravitium, a mineral that is unique to the planet Tyrian, and can control gravity. Microsol wants to use the mineral in their warships, which would make their army nearly unstoppable.
In February 2007, the original Pascal sourcecode was licensed to a small group of developers to rewrite into C, in a project called OpenTyrian, licensed under the GNU Public License. Following that announcement, in April 2007 Daniel Cook announced the free availability of his Tyrian artwork (not including the later work for the Game Boy Color edition and for Tyrian 2000) under generic liberal terms.
OpenTyrian was ported to the Dreamcast on February 24, 2008 by indiket. The first version had problems with music, and loading and saving was not implemented. This was corrected in the second version. The music is now played in WAV files. There is a slight delay when the Dreamcast loads the music and sound files, but this is only a few seconds. To save, a VMU must be in the first slot of the first controller, and a second controller must be present in order to save. To save, press start on the second controller. The latest release now also has support for two players. The instruction screen still causes the program to crash.