The original 1981 Donkey Kong arcade game features four distinct levels, each with its own set of challenges and layout. Not all versions of the game contain all four levels due to hardware limitations of some home system ports, but the full arcade version includes the following: 1. **Level 1: 25m (‘Barrels’ or ‘Girders’)** - **Name**: 25m, often referred to as the "Barrels" or "Girders" level. - **Characteristics**: This is the iconic first level where Mario, initially known as Jumpman, must navigate a series of platforms and ladders. Donkey Kong rolls barrels down the girders that Mario must either jump over or smash with a hammer power-up. Fireballs also appear as enemies on this stage. The goal is to reach the top platform where Donkey Kong is holding Pauline. 2. **Level 2: 50m (‘Factory’ or ‘Conveyor Belt’)** - **Name**: 50m, also known as the "Factory" or "Conveyor Belt" level. - **Characteristics**: This level introduces conveyor belts with cement pies (or 'pies') that move in opposite directions. Mario has to avoid these or jump over them while also dodging fireballs. His objective is to remove all rivets from the platform where Donkey Kong stands by walking over them, causing the section of the level to collapse and forcing Donkey Kong to move up. 3. **Level 3: 75m (‘Elevators’)** - **Name**: 75m, commonly referred to as the "Elevators" level. - **Characteristics**: In this unique stage, Mario must climb moving elevators while avoiding bouncing springs that Donkey Kong throws down. Timing is crucial here as Mario needs to leap onto and off of elevators at the right moments to progress. The goal is to reach the top platform to advance to the next stage. 4. **Level 4: 100m (‘Rivets’)** - **Name**: 100m, often called the "Rivets" or "Girders" level as well. - **Characteristics**: This is the final level in the cycle before the game loops back to the first stage with increased difficulty. Mario’s task is to move over all the yellow rivets, causing sections of the structure to fall and ultimately making Donkey Kong fall down. The level features fireballs as well as a new enemy, the rivet-removing creatures known as "Fires" that emerge from oil drums. After completing these four levels, the game returns to the first stage (25m), but with increased difficulty such as faster-moving enemies and barrels. The game continues to loop and become progressively harder with each cycle. All of these elements combined create a challenging and engaging experience for the player, which is one reason why Donkey Kong has remained popular for decades and is considered a classic in the video game world.