Viability: All the elements worked for me except the shooting! I think it is because I dont have a mouse but im sure it would work with one!
Presentation: Rules/instructions are clear as day. user friendly and you already warned us about the mouse movement which is the only thing that needs work!
Theme:Love the 3d space and the bridges to the islands. I wonder what kind of character you could make to be on the islands!
Engagement: Played it for a while just running around the islands! great demo