Episode 1

Episode 1 [also known as "Green Hills"] is the first world Red Ball 4 Series. New boxes like Evil Box and Ram Box makes their first appearances. This episode has no gimmick for this world.

Starting Cutscene
While 2 Red Balls are playing, a squarified Red Ball came, shocking 2 Red Balls. The squarified Red Ball said that it was those Evil Boxes who made him into a square. Then, it goes to the Box Factory, with an Evil Box making Red Balls into cubes. The earth then turned into a square, infuriating Red Ball and saving the world.

Ending Cutscene
The Monocle Boss explodes, and Red Ball begins jumping of joy. But, the eggs begin hatching, meaning that the adventure is not over.

Difficulty
Hence being the first world of the game, Green Hills is a very easy world with the first 15 levels being very easy.

Easiest Level: Level 1

Hardest Level: Level 14 or Level 15

Levels
Level 1 - No boxes - Very Easy

Level 2 - 1 Evil Box - Very Easy

Level 3 - 2 Evil Boxes - Very Easy

Level 4 - 2 Evil Boxes - Very Easy

Level 5 - 1 Evil Box - Very Easy

Level 6 - 2 Ram Boxes - Very Easy

Level 7 - 1 Ram Box & 1 Evil Box - Very Easy

Level 8 - 1 Ram Box & 2 Evil Boxes - Very Easy

Level 9 - 2 Evil Boxes - Easy

Level 10 - 3 Evil Boxes - Easy

Level 11 - 1 Evil Box - Very Easy

Level 12 - 2 Evil Boxes & 1 Ram Box - Very Easy

Level 13 - 1 Ram Box & 2 Evil Boxes - Easy

Level 14 - 1 Ram Box & 2 Evil Boxes - Somewhat easy/medium

Level 15 - Monocle Boss (summoned: 3 Evil Boxes & 2 Ram Boxes) - Somewhat easy/medium

Boss for this world: Monocle Boss Monocle Boss is not much of a threat with his "weak" boxes. But be sure to be careful if he summons two Ram Boxes, as they would ram you two times, taking away 2 hearts.

Trivia

 * This, in fact, is the only world to introduce two boxes, the Normal Box & Ram Box.
 * The instrument it uses, along with Deep Forest and Battle for the Moon, is the keyboard.
 * If one looks closely to Green Hills' background [only in levels], the houses resemble those "Philippines" based houses and the Nipa Hut.
 * There is a glitch in Level 14 where Red Ball still makes a sad face even if the player made it past the gap.
 * This is the only episode where the boss doesn't resemble the new enemy of the episode.