The player moves a trap around a circular field with the task of catching moving objects before they cross the field bounds.
The trap is the device controlled by the player. It is always centred at the bottom of the screen.
It can move only left or right, always at the same distance from the field center. (Visually, the effect is that the fields rotates according to the direction chosen).
The objects move from the center of the field towards its bounds in straight line. Their initial direction is unpredictable. There are 4 different kinds of object, each with its own color and speed; while colors depend on the theme, speeds are fixed as follows: slow, normal, fast and swift.
The objects are shot by a generator placed at the center of the field.
CATCHING AND MISSING OBJECTS
When an object has not completely crossed the bounds yet, it is said to be "alive".
If the center of an object passes through the beams between the trap sides, the object is caught.
When an object goes beyond the reach of the trap (shortly after passing the bounds), it is definitely missed. The game ends when the allowable misses (initially 5) are 0 and an object is missed.
|extra||kind||threshold(s)||what it does / how it works|
|pointer||automatic||3||marks the closest object with a special symbol|
|expansion||automatic||6, 80, 164||makes the trap wider|
|inverter||targeted||12||inverts the movement of the targeted object; each object can be inverted only once; inverted objects are marked with a special symbol|
|20||destroys the targeted object; overrides the inverter|
|freezer||targeted||30||keeps the targeted object nailed at its current position as long as the button is held down; objects, while frozen, are not affected by other extras; frozen objects are visually connected to the trap with a beam|
|speed-up||automatic||42||increases the trap speed|
|64||diminishes the speed of all the alive objects by 2/3rds; each object can be decelerated only once; decelerated objects are marked with a special symbol|
|guide||automatic||98||marks the critical object with a special symbol|
|118||makes all the alive objects rescuable; overrides the decelerator; when a rescuable object goes out of bounds, it is automatically sent back along the opposite direction and becomes non-rescuable again; rescuable objects are marked with special symbols|
|140||destroys all the alive objects; overrides the kickback|
|190||attracts all the alive objects to the trap until they are automatically caught; overrides the nuke; magnetized objects are not affected by other extras; magnetized objects are visually connected to the trap with beams|
As time passes by, the level increases making the game more and more difficult. The level is represented by 2 numbers, a major value and a minor value.
The minor value goes from 0 up to 99: as it goes up, the time interval between 2 consecutive shots becomes shorter and shorter. When it reaches 100, it restarts from 0 and the major value is increased by 1.
The major value affects the speed of objects (the higher the level, the faster the objects) and the margin the trap is given to reach objects (the higher the level, the smaller the margin).
Points are awarded when catching objects. The points assigned for a catch are directly proportional to the speed of the object, the current level, the current extras meter and the chosen difficulty.