While learning Unity, I wanted to develop something that would help me to better understand and utilize raycasting in a 3D space. At the time, I couldn't stop thinking about a room filled with birds and came up with the idea for a game where you would attempt to build a cage around a bird.
In practice, the movement of the bird was too erratic and speedy to make this an enjoyable experience. I pivoted instead to having pre-made cages that could be deployed around a bird in motion.