OpenTyrian app for iPhone and iPad

The game is set in the year 20,031. The player takes on the role of a skilled terraforming pilot named Trent Hawkins, who is employed to scout out habitable locations on newly terraformed planets. His latest assignment is the planet Tyrian, which is located near the territory of the Hazudra, who are a lizard-like race.

One day, Buce Quesillac, a Hazudra and Trents best friend, is shot in the back by a hoverdrone which quickly disappears into the sky. Buce lives just long enough to tell Trent that the attack was the work of MicroSol, the giant corporation that controls the terraformation of Tyrian. They want Buce dead because of his knowledge of Gravitium, which is a special mineral, unique to Tyrian, able to control the force of gravity.

Microsol wants to use Gravitium to power their warships, which could result in them becoming nearly unstoppable. They will stop at nothing to eliminate anyone who knows of its existence. Trent is the next person on their hit list, and Buce implores him to try to reach Savara, a free world. With that, Buce dies. Trent secures a small fighter, and departs for Savara.

Gameplay
Tyrian is an arcade-style vertical scrolling shooter. It was developed chiefly as a homage to the works of Compile, particularly their Zanac series.

The player controls a space ship fitted with different weapons (front and back, linked to the same button, and up to two external pods with their own buttons) and other equipment. The game presents a variety of enemies (some flying, some fixed, some on rails) and bosses, with many occurrences of fixed and/or indestructible obstacles. Before the players starship is destroyed it must take enough damage to exhaust several points of shields (which regenerate over time) and armor.

Tyrians full game mode features a credit and equipment-buying system, and the shield/armor hit points which are similar to game mechanics in Raptor: Call of the Shadows, another PC game from the same period. The arcade mode has characteristics from coin-op arcade shooters, such as in-game powerups and extra lives.

Difficulty
There are three levels of difficulty to choose from: Easy, Medium, and Hard, as well as the hidden options of Impossible, Suicide, and Lord of the Game. Hard difficulty and above employ enemies with more health as well as fire more bullets per second. Certain hidden levels are only available at hard difficulty, which provide ample opportunities for unique powerups and upgrades. In certain levels, the Hard setting also prevents the player from seeing enemies outside a conical line-of-sight. Upon completion of the game, the player receives a password for one of the several hidden ships, as well as the options for replaying the game at a higher difficulty setting.