"The Tone Rebellion is a science fiction real-time strategy game created by The Logic Factory. Released in 1997, it was the company's second release after Ascendancy, a space strategy game.
The Tone Rebellion is a pseudo-3D real-time strategy game with some RPG and puzzle-solving elements. Similar to Alien Legacy and Maelstrom, there is a plot that runs throughout the game and unfolds with progress. You are leader of the Floaters, jellyfish-like aliens fight to release the Tone, the life energy of the Floater world, from the grip of a force of evil called the Leviathan.
The game employs the theme of realms that determine the form and power of creatures that initiate from those realms. These realms have effects on both the Floaters and the Leviathan.
The Tone Rebellion also plays upon a strong "good versus evil" theme: the Floaters are pure, innocent and yet fighting for good, while the Leviathan represents an evil with no conscience, overcome by greed and hatred. "Leviathan" itself is a Biblical reference to a large, powerful sea creature. Long ago, when the Leviathan first attacked the peaceful Floaters, there was one large island and one kind of Floaters. During the attack, the island split into many smaller islands. The four surviving Floater tribes were stuck on islands far from each other, with each tribe believing no one else survived. Over time, the tribes began to develop differently from each other. Their goal, however, is to defeat the Leviathan and restore the flow of the "good" Tone, recreating the original island."
Source: Wikipedia, "The Tone Rebellion", available under the CC-BY-SA License.