Hidden weapon "Napalm"
If you clear the stage 1 boss by destroying only the engine unit and getting a score of 2800, napalm will be added to your arsenal. It is a powerful single-shot type that flies in a parabola and is extremely easy to use. However, it cannot be strengthened and will disappear when you continue.
Napalm reinforcement
If you obtain the napalm mentioned above, then destroy only the boss in stage 2 and clear it with a score of 5600, you will be able to strengthen the napalm to level 3, and it will remain even if you continue. However, in Stage 2, it is extremely difficult to achieve this condition because if you hit small debris, fixed artillery batteries, and mines, they will be treated as destroyed and your score will be added.
Infinite Continue
If you start by pressing [Up + L + R] on the title screen, the number of continues that should normally be 3 becomes infinite. As for the display, the credit part will be "FREE PLAY".
Gun angle adjustment
Press Start to pause, then press A while holding down [L+R+Select] on the 2nd controller to slow down the gun angle adjustment. Similarly, if you press X+Y while holding down [L+R+Select] on the 2nd controller, you can adjust the gun's angle faster.
Last bonus
After completing the ending staff roll and waiting for a few minutes on the screen where the high score is displayed, a scene in which a communication from the outer space exploration team is played will be displayed. This is a past work, and chronologically it represents the beginning of the future ``Heavy Armored Soldier Reinos (MD)''.
