Smiling Glass is a physics-based logic puzzle game. It tasks a player with making anthropomorphic glasses smile by accurately dispensing drinking water across 40 levels.
Each level features at least one glass and a gray water dispenser in front of a wall of graph paper. The player must fill the glass until the water reaches a dashed, horizontal fill line.
The game presents the player with a variety of obstacles designed to disrupt the flow of water or destroy it entirely, including red spiked platforms, rotating paddles and stationary horizontal, vertical and inclined boards. The player must often count the passing seconds and blocks on the graph paper to time the flow of water. For example, rotating cross-shaped paddles might turn left or right, or a moving spiked platform might turn upside down. The player fails a level if too much water falls off the sides or bottom of the screen.
The player must have excellent hand-eye coordination, knowledge about gravity and physics, and timing to win. They must also have an abundance of patience. In some levels, the player doesn't dispense the water in a stream. They must patiently release it as droplets or short flows.
That said, Smiling Glass counts a glass as full if the player manages to fill it beyond the fill line on only one side. The game counts it as long as the water above the fill line on that side equals the volume of the remaining empty area under the fill line on the other side.
