Neuron Jungle is level 4-4 in Yoshi's Story. It is the only known place to have Frogs, Neurons, and Ick Worms. These are all nocturnal creatures, but since it's always dark in the jungle they thrive. The background music is "Jungle Fever", the same one as in 4-2, Jungle Puddle. This is the only other given name to a Jungle area other than the Piranha Grove.
The level consists of many Neuron obstacles, while the Neurons can help the player get around or stop them from progressing and even cause the player to fall into oblivion. These jelly-like creatures are obviously the main attraction to this level, and provide a bizarre feel to the whole setting. The whole area seems to be high up in the jungle, for a wind noise that often indicates great height in the game constantly can be heard throughout the level, and when the player falls, they ultimately lose. For these reasons, the level does not consist of one large path, but mostly numerous platforms to jump to and from.
The Neurons can be found blocking spaces and fruits, while also being helpful platforms to reaching other ends of gaps. Some move on their own, while others only move when the Yoshis ground pound on their heads.
There are two parts in this level that are not high up in the jungle sky, but instead, down near water. Most of the frogs dwell here, and Neurons become less seen in these areas. It is noticeable that, in difficulty, the frogs are an evident replacement for the large Blurps in the other aqueous jungle level, Jungle Puddle, for they provide the danger in the water that the Blurps previously did. Fortunately, the frogs can't take out the Yoshis in one blow like the large Blurps.
Another section of the level is filled with Sea Cacti on the ground, rather than in the water. Numerous Sea Cacti are lounging around, while again, no Neurons are present.
Strange creatures come out at night, and, in the jungle, it was always dark. Neurons lived in this jungle, but they weren’t as wild as they appeared. Instead, the Neurons were quite tame, and they happily helped the Yoshis escape.
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