Kage uses a side-scrolling perspective across five stages, each divided into several areas filled with soldiers, creatures, traps, and bosses. Hayate and Kaede can run, jump, crouch, cling to some surfaces, and attack with a sword or collected weapons.

Weapon pickups include the kusarigama, shuriken, and bombs, with stronger versions available after repeated pickups. Players advance by reaching each area's exit, defeating bosses, and managing limited health and weapon ammunition. One- or two-player cooperative play uses the same screen, so both ninjas must stay within the camera's range.

Use the sword against nearby enemies and conserve bombs and shuriken for armored targets, crowded platforms, and bosses. Repeatedly collect the same weapon to improve its power, but avoid replacing a useful weapon without checking the surrounding terrain.

Crouching helps against some projectiles, while careful jumps are essential on moving platforms and narrow ledges. In two-player mode, keep Hayate and Kaede close enough to remain on screen; rushing ahead can force the other player into hazards or enemy attacks.