Sengoku is a side-scrolling fighter in which the player can change between their basic characters and a set of special characters for a limited time. The game is separated into a series of individual scenes within levels; the player must defeat all the enemies in one scene before moving on to the next. At various points in the level, the player will be transported between two worlds. The first world is a ruined Japanese city, with looted storefronts and demolished buildings. The second world is the spirit world, either up in the clouds or in some sort of underground cave.
During the course of the game, the player can acquire three helper characters: a sword- wielding samurai, a somersaulting ninja and a dog that can attack with spins. Helper characters can be recruited by defeating certain enemy characters. Once acquired, these characters can be used any number of times in a level for a combined total of 60 seconds. But if the player dies while using a helper character, they lose that character and must reacquire him later in the game. The player can also collect colored globes discarded by fallen enemies that equip players with swords or fireballs for a limited period of time.
The player begins with a number of health blocks. When their character is knocked down, they lose one health block, and when all their health blocks are depleted they lose one life. The game ends if when all lives are lost.