Is a Main Camera Necessary?

I have a 2D project that just uses Canvas objects. If I disable the main camera, everything works, but there is a warning in the Editor about there not being a camera in the scene. Is the main camera necessary? Does it add any unnecessary overheard?

I’ve had this problem before. Basically it sums it down to this: Unity is built and optimized for 3D-2D games, not something simple like a UI game/app. Basically you don’t really need a main camera, but Unity’s gonna be mad until you add one in. In my opinion, it’s better to make a game with 2D sprites than UI. The biggest plus is that you can move a camera around, or attach the camera to another game object. You can’t do that in UI! If you needed to simulate moving a camera or a shaking effect, you’d have to move everything in the scene at once, and that’d be a real pain. But if your game/app is just Tic tac toe, Unity is overkill anyways. If you really want to keep it that way, just add a camera in for now and remove it before the final build, it wont hurt any.