Hey You, Pikachu!

Hey You, Pikachu! is a simulation game in which you talk to Pikachu (quite literally). Notable for being the only N64 game released in America to use the Voice Recognition Unit (VRU), which is Nintendo-speak for "dopey-looking microphone".

No PlayStations Allowed
In reference to Nintendo's ongoing rivalry with Sony, saying "PlayStation" causes Pikachu to get angry, as if he was insulted.

Regional Differences
The American version has several changes from the Japanese one. A PAL version wasn't released due to trouble with recognizing various accents all at one time.

Pokémon Cries
Every Pokémon except Pikachu, Caterpie, and Butterfree have different cries between the two versions. This is because the Pokémon go by different names between Japanese and English, and the voice work was changed to match the dubs of the animé.

Player's Home
Right outside the sliding glass door of the player's room are a pair of shoes in the Japanese version which are nonexistent in the US one. In Japan, people take their shoes off before entering their homes, a tradition which America doesn't follow so strictly.

The Nintendo 64 in the Japanese version looks rather unpolished and appears to have Super Famicom cartridges with it, which doesn't make sense (N64 cartridges are the same in design between America and Japan).

The fishing posters that the player receives are different in design between the two versions.

Item Changes
Certain items that the player and Pikachu can play with are different.

The onigiri (riceball) that resides in the Toolbox by default was changed to a cupcake in the US version.

The Japanese version has eggplants, whereas the US version has corn. The result is that Japan misses out on popcorn which is obtained when Pikachu shocks the corn.

In Viridian Forest, the player finds Cattails rather than Horsetails.

In Springleaf Field, the Morning Glory in the Japanese version became a Bluebell in the US one, although the models remain unchanged since it's just a texture swap.

"No Microphone" Icon
In the Japanese version, the icon in the lower right-hand corner of the screen for not having a microphone plugged in is small and static. The US version increased it to a more decent size and animated it, since apparently it's very difficult for Americans to realize they haven't plugged in one of the main aspects of the game.

Piñata Game
In the US version, going to Cobalt Coast in Pikachu's Play Days leads to a Piñata party where Pikachu has to hit a Pokéball Piñata. In the Japanese version, Pikachu instead plays a similar game called Suikawari.

The objective of the game is to hit a watermelon with a stick, with Pikachu wearing Satoshi (Ash)'s hat from the animé to cover his eyes. As such, there are watermelons scattered around along with the bananas, and Pikachu has to hit the watermelons. Pikachu can trip on the watermelons a couple times before he actually has to quit the game, whereas tripping on bananas is an automatic game over.

If Pikachu loses, he gets a soda can tab in the Japanese version and a bottle cap ring in the US one.