In the Japanese version, Area 1 is Old Capital and Area 3 is Material Factory. However when the game was localized, the stages were swapped for unknown reasons.
Contributed by Ophl
There is a hidden and incomplete 3D Effect function that can be unlocked from the title screen by inputting the following sequence: Select, Select, A, B, Select, Select, X, Y, Select, Select, L, R, Up. If done correctly, the HyperZone title will change from orange to red. The effect can then be toggled in-game by pressing the Select button. It appears the idea was to make use of Anaglyph 3D glasses (red/blue) for a 3D effect, but the effect was not fully implemented and ultimately abandoned.
Contributed by G-Haven
Attachment
The flashing "chips" in the first level (Material Factory) are the same block-based shapes used in Tetris. They are even uniquely colored to differentiate them from each other.
Contributed by G-Haven
Attachment
"Lolo" from the Adventures of Lolo series can be found as a place-holder sprite amongst the various spaceship sprites.
Contributed by G-Haven
Attachment
The boss of the third level, Old Capital, is a SNES button pad, with the four colored buttons spinning around the central pad.
Contributed by G-Haven
Attachment
In the game's ending credits, some of the chips have "HAL" labeled on them, which refers to the development studio (HAL Laboratory) that created the game.

Another of their logos can be seen on an enemy/obstacle named "Box" on the first level of the game (Material Factory). "HALKEN" is composed of "HAL" and the first part of "kenkyuujo", which means "research laboratory".
Contributed by G-Haven