The gameplay world is rendered in 3D, and at key points an in-game cutscene plays in which the camera and plane move.

[4] As the game is marketed as a bullet hell shooter it features four difficulties: normal, challenging, hard and insane.

[6] Players can choose from multiple characters and planes, and the combination of choices determines the vital statistics during play.

The first features a father bent on taking revenge on the Empire that executed his son for being the sole pilot that refused to drop a nuclear bomb during an attack on the Enkies.

Albeit originally split into four great nations, by the time the plot unfolds two factions are locked in the Eternal War: the aggressive and dictatorial Layil Empire and the Atarach Kingdom of the Enkie race.

The apparatus is capable of arbitrarily accelerating an item's or even living being's time flow to the point of literally erasing it from existence.

Stored inside the floating fortress-city of Siriad, the Project uses every military vehicle of the Layil as a relay, creating a weapon that cannot be effectively disabled.

This advantage has allowed the Empire to cut through Enkie defenses, culminating in a vicious (presumably) nuclear bombardment of the Atarach kingdom.

In the "normal" narrative, which encompasses the player's first playthrough, Ronotra Koss is mourning the death of his son, Argus Pytel, at the hands of his crewmates as he refused, during the flight of the bomber Cobalt King, to drop a nuclear bomb upon the Enkie capital city; embittered and vengeful, Koss mans a stolen Sine Mora school "Merenstein" plane and, with the help of a smuggled combat artificial intelligence, GARAI 74/22876, starts to systematically infiltrate Layil Empire structures and eliminate officers involved with his son's demise, all the while exacting a bloody revenge on the Empire which abandoned him after an incident left him an amputee.

Finally reaching the city of Tira, capital of the Empire, he mercilessly destroys most of its military force, finally facing the colossal Domus assault fortress manned by the officer who killed Argus, managing to destroy it after maneuvering through its defenses and blowing up the power cores.

The parallel storyline involves Akyta Dryad and an ensemble of surviving Enkie resistance fighters unleashing a series of guerrilla attacks on the empire, bent on stopping the Project.

Resistance fighters fall one after another, either captured or killed in action, dealing a series of crippling blows to the Layil who, however, seemingly recover from each with minimal actual consequences save for structure damage.

Infiltrating Siriad, the Empire's floating fortress-city, Akyta, then the sole survivor, reaches the main chamber housing the Project apparatus; there, she is horrified to find two million Enkie survivors connected to machinery, heavily drugged and genetically altered, their natural time manipulating capabilities being channeled to fuel the Empire's temporal gravitation weapons.

Fighting the facility's guardian and controller, Ophan, she manages to end the threat of the weapon, leaving Layil unable to use time manipulation.

In a shocking twist however, the entire chain of events is revealed to have been engineered by none other than Argus Pytel himself: a top ranking intelligence officer and a Collaborationist, he engineered for both Resistance groups to embark on suicidal missions, confident of the Empire's chance to recover quickly from any damage via its control over the timeline.

The rebel crew member aboard the Cobalt King was actually killed by Pytel and not the other way around, a fact he took advantage of to trick his father's faction into action.

The plan however took yet another unexpected turn when, surprising the attacker of the Domus and shooting him down with a barrage of missiles, he was horrified to discover he had just killed his own father.

The "alternate" narrative is more of an alternate ending: following his father Ronotra Koss' death by his own hands, Argus starts devising a plan of his own to exact revenge on the Empire: using his knowledge of past events and the Project equipment, he traveled forward in time to before Akyta could destroy the Ophan, having her travel 4200 years into the past and saving her life before destroying the facility himself (and dying in the process).

The boss battles for the game were initially designed in large part by Mahiro Maeda, an anime artist known for his work on The Animatrix, Kill Bill, and Neon Genesis Evangelion.

Reiker cited several bullet hell shooters, such as Battle Garegga, Einhänder, and Under Defeat as influences for the game.

[19] VideoGamer.com's Sinan Kubba also praised the boss fights, citing the multiple attack sequences and 3D transitions as high points.

Daemon Hatfield of IGN noted that the game is detailed enough that players "can see each individual shell drop from [their] ship as you fire".