Happy Glass

Happy Glass is a physics-based drawing puzzle: sketch lines to redirect liquid falling from above so it lands in the glass and fills it to exactly the right level, neither overflowing nor falling short. Because the drawn lines act as ramps and barriers, the shape and angle you sketch determines exactly how the liquid's path bends on its way down toward the glass. A line drawn at the wrong angle can send liquid sliding past the glass entirely, so testing an angle mentally before committing to the drawing usually beats a rushed, imprecise sketch. Later levels add more obstacles and awkward gaps for the liquid to navigate, which means tracing the full intended path from source to glass before drawing anything pays off.