Impulse is a logic puzzle game for Windows and Mac OS X. Each level consists of simple geometric game objects, user controllable bombs and a ball. One of the game objects is the goal object which you must hit with the ball to finish the level. The ball is controlled indirectly through the placement of the bombs. Some game objects have special features and give bonus points for example. Special areas of the game change the direction the ball is moving if it comes into their influence. The ball is always under the influence of gravitation which can change from level to level. The first step is the setup. You can place the bombs inside the level and move them around. Some bombs have a timer that can be adjusted to control the time of explosion. The key element of the game is the interactive timeline. It allows you to jump to specific points in time and helps you to correct the timers of the bombs or move them to a better position. The second step is the simulation. Once started the ball moves according to the physical influences. The gravitation for example acts upon the ball, while the bombs from the setup step catapult the ball into a new direction when they explode. In this step you can just watch if the ball moves where you intended it. You have no direct control over the course of action. But you can stop the simulation step anytime and return to the setup step to adjust the position and explosion times of the bombs. Once the goal object is hit the level is finished. A summary is displayed with the achieved score. The score consists of the expired simulation time minus the bonus you got through hitting bonus objects along the way. One specific feature of Impulse is that the lower the score is the better you are - even negative scores are possible through bonus objects. Afterwards you can directly play the next level or you can try to adjust the bombs again to achieve a better score in this level.