Umbra: Shadow Warriors was designed as a companion game to Umbra: Tree of Life. The objective behind the design was to incorporate the mechanic of casting shadows, and the themes of uncertainty and strategic maneuvering, into a traditional board game. What resulted was a game in which players slowly explore the space on-screen to discover shadow challenges, which must then be completed in order to win tokens. Certain combinations of tokens are worth more than others.

The shadow challenges require players to assemble 3D objects on a transparent surface in order to cast a shadow that matches the outline shown beneath the token. Players use a flashlight to cast the light. The flashlight can be held at any angle, and every shadow challenge can be completed through a variety of orientations of the 3D shapes.

In Umbra: Shadow Warriors, our story of an impending conflict in the world of shadow people returns to the forefront. As chieftains of separate shadow tribes, players compete to recruit powerful warriors to aid them in the upcoming battle against the evil Penumbra. These warriors commit to whichever side can construct their respective shadow dwellings first (completing the shadow challenge). When the shadow dwellings have been constructed, the warriors offer a token to the player to declare their allegiance to the tribe.