Hydra is an arcade video game where players are piloting a hovercraft, trying to deliver top secret items while avoiding mines, other hovercraft, and logs. In Hydra thieves are trying to steal the treasures from a museum, these artifacts contain secrets to a weapon and it is your job to stop them. The player is issued an experimental speedboat to navigate the rivers in order to retrieve the treasures from checkpoints. There are nine levels of rivers and oceans, while playing the game the player can collect money bags for extra cash and crystals for extra fuel.