Rygar

Walk above opponents:
Jump on a pile of stones, then hold Fire to walk in mid-air above your opponents.

Cheat mode:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.

POKE 9551,165
POKE 4050,77
POKE 4055,77
SYS 2325

Unlimited lives:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.

POKE 9551,165
SYS 2325

Unlimited time:
Load or reset the game, then execute the following BASIC commands before running or restarting the program.

POKE 4050,173
POKE 4055,173
SYS 2325