"Hammer" is about smashing squares with a rectangle.
The player controls the horizontal position of the hammer using the mouse and uses it to smash targets.
The hammer starts in the middle of the screen and can only be moved left and right.
Targets (squares) appear from the bottom and top of the screen. Their velocities are random, and they can bounce off walls. (Their direction of movement should not be so horizontal, however, that they move incredibly slowly vertically) Targets cannot collide with each other. Targets will appear at an increasing rate and velocity as the game goes on (probably to some max).
Targets can be smashed with the sides of the hammer but not with its top or bottom. The player gets a point for each target smashed, and the hammer's length grows slightly (probably to some max). (Options: 1. The hammer may need to be moving at a high enough velocity to smash the target; otherwise, it just pushes it. 2. Targets can also have health and award different amounts of points) If the top or bottom of the hammer gets hit by a target, the hammer is damaged and the length of the hammer shortens. (Options: 1. Targets that touch the hammer blow up (no points). 2. Targets that touch the hammer bounce off of it. 3. Hammer gets stunned in place for a short while 4. Hammer doesn't get damaged from being hit by a target)
The length of the hammer will drain over time and blow up when it becomes a square, thus ending the game. (Option: After the hammer becomes a square, the hammer will turn red gradually until it blows up. The hammer can still be saved by smashing targets but will break if hit by a target on the top or bottom)
There needs to be some sort of pause + shattering effect before the targets or hammer breaks -- it would look silly if the targets simply disappear.