Insector X (NES)

Secret Message
Enter the "OPTION MODE" menu, then move the cursor to the "EXIT" option. Press Right 35 times, then press Left once. The message, "PRGD. BY JYOJI HIRAYAMA" will appear.

Level Select and No-Hit Mode
Enter the "OPTION MODE" menu, then move the cursor to the "EXIT" option. Press Right any number of times except 35, then press Left. At the "BOY/GIRL" select menu, press Up to cycle through the levels, and Down to toggle "HIT/NOT" mode, to play with normal lives, or invincibility, accordingly.