Really the only noticeable addition to Hercules' gameplay (as
opposed to Zelda's) is that there are two additional playable
characters: Iolaus, Hercules' long-time friend, and Serena,
Hercules' love interest turned Golden Hind. Iolaus, due to his
smaller size, is able to do things (such as climb vines) and access
areas that Hercules isn't able to. Serena is an archer, and thus she
provides the ability to take out enemies in places that Iolaus'
staff and Hercules' punches can't reach (including a
decent sniper
mode).

The game itself is largely story-driven, and is largely based on
the TV series. Hera (Queen of the Gods) has poisoned Zeus and Ares
(the God of War and son of Zeus) sees this as an opportunity to take
over as King of the Gods. A power struggle develops, and most of the
other lesser gods (who sense that something is up) leave Gaea to
investigate. This throws the world into turmoil, and Hercules is
left as the only one who can protect mankind from evil. As Hercules
travels through the land and rights wrongs, he'll meet up with many
different characters found in the TV series. This makes the
storyline familiar to fans of the series, but unfortunately the way
the storyline advances is sometimes poorly implemented. In each area
there's usually one key person who you need to appease (ex: in the
first town it's a guard who misses his teddy bear) before you can
proceed, but often you aren't given a clue as to how to go about
doing that. Thus you end up wandering around town until you finally
stumble upon what you need to find to appease that character to
advance in the game.
On the whole the storyline holds up fairly well. This is mainly
due to its familiarity and the way the characters interact with each
other. The humor found in the TV series is intact here, and the
result is an entertaining story with lots of hilarious dialog. Each
of the characters that make cameos here (such as Aphrodite)
maintains the same characteristics as their TV counterpart and that
helps immensely in replicating Hercules' world. If you enjoy the
humor in the series, you'll enjoy the humor in this game.