Altering Your Island

Your new island will probably look like a small mountain with a few rocks scattered around it.
Move the mouse on and off your island - you should notice a green box appears around the island. This will be useful later on for indentifying which tile you have selected and which you are about to select once your islands start to overlap.
Click your island.
A new window titled Landscape Tile should open up - This contains all the variables you need to alter your land.
There are quite a few options here:

Works just like the Generate button in the Landscape window.

Does exactly what it says on the tin. This will give your island a new 'Random Seed' (see below), thus giving you a whole new island.

Deletes the island.

Creates an exact copy of the selected island, slightly off-set from the original. You'll want to move the copy out of the way and into a more suitable position.

This enters GuideGrid mode, which I will cover in more detail later on.

Noise Period
Noise Scale
These 2 options alter the way your island is generated. It's hard to describe the exact effects caused by altering these values, as the effect of changing it seems to vary on the island, and the current range of the value. Extremely low numbers in Noise Period will cause your island to form lots of small jaged points, and larger numbers will form 1 or 2 distinct peaks on your island. Noise Scale seems to simply alter the scale of these points. The best way to understand it is to change them between extremes and see the effect yourself.
Allowed values range between 0.00 and 10.00.

This changes the general height of your island. The default is 200, and you will probably find this is too high for creating an island that you can place units or buildings on. Between 30 and 50 is a good height to make reasonably flat areas for your level.
Allowed values range bettwen 0.00 and 1000.00

This is one of the most important factors in determining the way your island looks, as it changes the method used to generate the tile. You can use 3 values, 0, 1 or 2, and I will cover each in more detail shortly.

Lowland Smooth
This is a very odd variable, as its effect changes dramatically depending on the current shape of your island. Basically, it alters the smoothness of your terrain. The way this variable changes your land seems to depend on how much flat area there is. Small but steep moutain like islands normally aren't effected by changing this in any major way, however if you have multiple small, flat islands, the tile may change dramatically - some islands might vanish and others will become sharp and pointy. Again, its best just to play around with this and see the effects for yourself.
Allowed values range between 0.00 and 3.00

Pos X
Pos Y
Pos Z
This is the position of your island on your level. You can change X and Z simply by clicking and dragging your island around the map. Changing Pos Y will cause your island to rise up, and will form almost vertical cliffs around the edges. The default Pos Y is 0, and generally it's best to leave it at this - the effects of changing it can look very odd.

This scales your island up or down while keeping the shape the same.

Random Seed
This is the variable changed by clicking the Randomise button, but you can enter your own values into it if you're so inclined. There is no real way of predicting what changing this will do to your island, and if you are simply clicking the randomise button and find an island you like, it would be a good idea to, at the very least, note down the random seed, otherwise you might not be able to get it back.

Using these options, you should be able to create any kind of island you can imagine, with a little tweaking. However, as I mentioned, the most important variable is the Method option. Each value for method will give a completely different kind of island from the same random seed:

Method 0
Islands generated using Method 0 tend to be large islands, with a tall peak in the middle, and flatter areas spreading out around the bottom. Sometimes more than 1 peak is generated, and this completely changes the rest of the island, however. With more than one peak, islands range from small moutains sticking out of the ground to large mounds with rocky outcrops on the edges. By reducing the height of a Method 0 island, you can easily create lots of land to be the base of your level.

Method 1
Islands generated using Method 1 are generally like moutain ranges. Somtimes there is flat land around them similar to Method 0, however it is more uneven. The range of moutains generated is huge - sometimes they fill the entire tile with random peaks, sometimes its just a solitary spire in a corner, or maybe a valley with moutains rising up around a flat area in the middle.

Method 2
Islands generated using Method 2 are very random, very steep cliffs, with relatively flat tops. There also tends to be some flat land around the base of these cliffs. Method 2 generates the most interesting islands, though also perhaps the most unuseful ones. You will probably find that you will use Method 2 less than the other 2 in most cases.

Using a combination of these 3 Methods, you can create pretty much everything you've seen playing through Darwinia.