Over Horizon

Over Horizon is a sidescrolling space shooter by Takara in the vein of Gradius and Life Force.

Sound Test
Hold Select + Start + Up and press Reset.

Extra Graphics Mode
Holding A + B at the title screen and pressing Reset will net you this bizarre alternate graphics mode where you control a Samurai and horses battling with katakana; in addition, there are even more insane graphics in the Japanese version (it appears they cut out quite a few graphics for the European version).

Unused Boss Design
Appears to be an unused design for the final boss. Creepy.

Draft Ending Animation
Game Genie code enables a sequence accessed by pressing Start at the title screen. It appears to be a draft of the original ending with the unused boss, as the staff roll begins afterward.