Mysterious aliens — Insignians — plan to conquer Earth. They built a number of factories and warbases on an asteroid. Factories make components, bases assemble them into robots. What's unusual, is that Insignian military controls only the warbases, but the factories are owned and operated by private contractors, who sell components to the military. That's their weakness.
Fortunately, Earth forces were able to capture one of the warbases and Earth managed to raise several "space dollars". You must buy robot parts, assemble robots and capture other 3 warbases. Earth will send more money, but not enough. Capturing the factories that make robot parts is a cheaper way of building your army. To do so, park your robot in the factory entrance long enough (12 game hours) to declare a martial law, thus capturing the factory. Unfortunately, after you arrive, Insignian military starts capturing neutral factories too. But fear not: the corrupt Insignians will still sell you components, even if all factories are held by the enemy.
You are piloting an invincible "command module", that can fly anywhere on the map. To access a robot assembling menu land on the roof of your warbase. To reprogram your robot or to directly pilot it land on the robot.
Robots can walk around the field following simple programs (e.g. "Find and capture neutral factories", "Find and destroy enemy robots", "Advance 9 miles"). Or you can control 1 of them directly.
There were several unofficial remakes:
- In 2002-2005 a cross-platform remake was written, also called Nether Earth. Open-source, under "as-is license", also included in many Linux distributions.
- An unrelated commercial remake for iOS Battlefield Moon appeared around 2010.
- And another open-source remake Nether Earth Q started recently on SourceForge, but hasn't been active since spring of 2012.
- There was also a flash remake, but its site disappeared.
Contains examples of:
- Area of Effect: "Nuclear bomb" weapon destroys everything on the screen. Including robots, artificial obstacles, factories and bases.
- In the 2002 remake it affects only a 5x5 square without corners (like city area in Civilization).
- Artificial Stupidity: Pathfinding leaves a lot to be desired.
- In-game: "electronics" component is optional, but robots without it are dumber.
- A Winner Is You: At least in Spectrum version and 2005 remake. Same for losing.
- Bottomless Magazines: Robots never run out of energy (for phasers or engines), missiles or cannon shells. Almost justified by their rather short life expectancy.
- Colour Coded Armies: Averted. All robots had the same color, probably due to Spectrum hardware limitations. Even flags on captured bases were the same and differed only in placement.
- 2002 remake colored robots and flags blue and red.
- Conservation of Ninjutsu: If the robot is controlled by an experienced player. It is possible to win the game with just 3 robots: 2 autonomous with "Capture Neutral/Enemy Factories" tasks, 1 human-controlled to kill the enemy army and capture bases.
- Corrupt Corporate Executive: Factory operators gleefully sell components to both sides.
- Everything Breaks: Any artificial structure can be destroyed, at least with a "nuclear bomb".
- Easy Logistics: Robots don't need refuelling or rearming, and they cannot be repaired or upgraded.
- Enemy Exchange Program: The central idea of the game. Capture enemy production facilities to build the military equipment, which was intended to invade Earth.
- Fog of War: You can only see the immediate area around the command module, plus the radar shows several screens around it. To look around you need to fly the module there. However, robots on both sides can sense their targets even beyond the radar range.
- Game Mod / Expansion Pack: The original game did not have an editor, but harder maps were created anyway. (Some can still be found on Spectrum sites.) Open-source remake also has several maps available in addition to the classic one, and they use text format.
- Hover Tank: Robots with an "anti-grav" chassis.
- Insurmountable Waist-Height Fence: Even an anti-grav will not let you climb over artificial obstacles. Though you can shoot over them, if they are low enough. Climbing natural mountains is allowed for non-walkers.
- Mighty Glacier / Fragile Speedster: At least, that was the intention. Slower chassis have more hit points. Not enough to compensate for bipod's slow movement and turning.
- Redshirt Army: Both sides.
- Ridiculously Fast Construction: Or, to be more precise, ridiculously fast delivery of appropriated parts and instant assembling of robots.
- Some Dexterity Required: Landing the command module on a moving robot isn't easy. Especially when the robot constantly changes direction. Especially if the robot got stuck and is running in circles.
- More so for combat mode, but that is optional, you can win just with building and programming robots.
- Speed Run: Since the game is fairly easy for an experienced player, self-imposed challenges abounded. Some people claim winning in 8 game days.
- Suicide Attack: "Bipod" + "nuclear bomb" = cheap suicide bomber robot. Although you could build a powerful Hover Tank for the same price.
- Tank Goodness: Though they are called "robots" they are more of tanks rather than Humongous Mecha. Especially the ones with "tracks" chassis. (Which is a reasonable compromise between price and cross-country ability.)
- Trope Maker: Real-Time Strategy.
- Units Not to Scale: More or less averted. Factories and bases are several times bigger than the robots they make. The asteroid is very long and very narrow, only about 8 times wider than a robot.
- Then again, if the asteroid is so small, where do the factories get the materials?
- Walking Tank: You can build walking robots, but the "bipod" chassis is slowest and cannot pass cracks or mountains. Although it's cheap, therefore useful for Suicide Attack.
- We Have Reserves: One possible strategy. If you already have enough factories, you can assemble robots faster, than enemy destroys them, without spending money.
- With This Herring: You start the game with 20 space dollars — that's all Earth has. Additional 5 dollars arrive each game day.
- Zerg Rush: Hard to organize, since landing on each robot to reprogram it takes much time, and the group disperses. Besides, the original map has multiple bottlenecks and choke points, that force the advancing army to enter open areas one by one and vulnerable to fire from several sides.