Doll ~Uroboros ni Na o Tsuraneru Mono~

The medieval country of Ouroboros is in trouble. An evil earl has been oppressing the population, imposing heavy taxes and establishing an iron rule. This led to tensions with a neighboring country, who thought of a simple solution: send an assassin to the earl and kill him. The assassin they chose is a highly skilled swordsman named Noel. But as Noel arrives at the earl's castle, he realizes killing him won't be a simple matter. He'll need help, and maybe it will come from a certain young lady and from a mechanical maid in the castle.

Doll: Ouroboros is composed mainly of a huge 3D movie, with some interaction between watching the clips. The interaction is confined to making a decision (a wrong decision will usually lead to Game Over), and choosing one of the several available paths for Noel to take.