The package can be installed by using the following commands:

sudo apt-add-repository ppa:mqchael/opentyrian
sudo apt-get update
sudo apt-get install opentyrian

To play the game you will also need to install the necessary data files of the original Tyrian game. Since they are published as freeware, but not as open source, they are not directly included in the package. However, you will be asked whether the files should be downloaded automatically during the installation (except for Trusty) or if you want to do this step manually. If you choose a manual installation, it is recommend to execute the following commands:

sudo mkdir -p /usr/share/opentyrian/data/
wget http://sites.google.com/a/camanis.net/opentyrian/tyrian/tyrian21.zip
sudo unzip -j tyrian21.zip -d /usr/share/opentyrian/data/
rm tyrian21.zip

You can now launch OpenTyrian from the menu (it should be under Games, but some desktop environments put it under "Misc") or via the command line (just type opentyrian).