Here is an overview of the game, via its store pages:
When he realized it, he was in the darkness, unaware of even which way is up or down.
How long had he been here? And how long will he remain here?
When his voice didn’t reach anyone and it seemed like even the consciousness he had left was starting to fade, a ray of light shined in the darkness.
He heard someone calling…
Driven by that voice, he desperately reached out to the light, only to see an unknown starry sky before him.
And in its arms a girl with red eyes and two horns pointing up to the heavens.
The girl, bleeding without an end in sight and hovering between life and death, asked him this.
“A black mask…? You’re… my….”
A rebellion, of a princess bound by blood and a man who lost his name has begun.
Deploy up to five characters in your advance and rear guards, and begin the battle. The attributes of each character in your formation are the keys to victory. Battles play out automatically. Each character has a unique skill that can be activated when the gauge at the bottom of the screen accumulates, making for extremely flashy battles.
A great number of unique characters, represented by a cast of wonderful voice actors, appear in Utawarerumono: Lost Flag.