Random things that don't really fit in any of the other sections.
UNUSED BIO PLANT BACKGROUND TILES
Stored with the background tiles for the Bio Plant stage are tiles for a strange, unused bio mass and a similar looking tile with a grate covering it. Judging from these titles and the stage's name, the Bio Plant was probably supposed to be more "organic" than the final version, but this was scrapped in favor of the pretty flashing lights.
There is also a darkened-out tile of just the mid-section of the bio mass. This probably indicates that the tile would have been animated to light up, just like the flashing light tiles that actually were used.
The following text is located at offset 0x3ABC4 in the Japanese version's ROM:
NAK1989 S-CG-CADVer1.22 9b0.26
It appears to be referring to a development tool. A similar message can also be found in various other Super NES games, such as Super Mario All-Stars.
Unused text discovered by BMF54123.
One thing that's kind of funny about HyperZone is that each time you get a new ship, the dashboard at the top of the screen will change design to reflect the new ship. What you may not notice, because it's a little more subtle, is that each ship has its own "warning message" for when you're too low on power.
BM4: Condition Red
H Wing: Warning
RW 91: Danger
My personal favorite is the BM4 Reform's message.
X 003: Power Down
BM4 Reform: Look Out!
The opening demo shows the CPU-controlled H-Wing ship charging up and firing normal shots at the same time. This isn't possible for a human player to do during normal gameplay.