Reading the code, some major points:
Planets have gravity (although it looks like it requires mass blocks to take affect unless there are changes I missed looks like it does!)
const float GRAVITY_AT_CORE = 4.0f;
const float DEFAULT_GRAVITY_RADIUS_KM = 50.0f;
Gravity varies based on your distance from the core
public Vector3 GetWorldGravity(Vector3D worldPoint)
Planets can have an atmosphere
bool m_hasAtmosphere = false;
float m_maximumOxygen = 0.0f;
Planets can have flora (appear to be randomly generated). There are three densities (LOW, MEDIUM, HIGH).
public void SpawnFlora(Vector3D pos)
Planets have orbitals
Vector3D PlaceToOrbit(Vector3D pos,ref Vector3D gravity)
Atmospheres have visual wavelengths, random shifts from red, blue, and green.
public Vector3 AtmosphereWavelengths
Planets can have mooooons (at varying sizes and distances)
private const int MOONS_MAX = 2;
private const int MOON_SIZE_MIN = 8 * 1000;
private const int MOON_SIZE_MAX = 10 * 1000;
Planets can have polar regions with ice fields
private static MyMaterialLayer CreatePoleLayer
Planets are setup to have specific ore probabilities in 5 to 8 layers.
Planets are setup to generate hills and canyons as features.
Planets have a probability for hostility
<HostilityProbability>0.6</HostilityProbability>
If there is too much pressure inside an atmosphere, you will take damage
if (EnvironmentOxygenLevel > Definition.PressureLevelForLowDamage)
There's an actual sun now, and you can change its day duration. The new sun is optional on world creation. This may only be for ME for now(?).
other changes:
Scenarios now have a hotjoin flag ("Can you join a running scenario?") and a new packet to accommodate this.
New methods for imprecise collision detection between spheres and voxel bodies (probably for "ship hit the planet scotty")
New checks for disabling block destruction. Solar wind will no longer deform blocks if it's set.
Many new world creation fields, and many new debug fields.
Scenarios have new timeout options (3 min, 5, 10, unlimited)
There are new flags to disable blocks in survival mode and to hide them from your toolbar.
New scenario conditions (ALL_OTHERS_LOST)
Scenarios can display different win and lose tips.
New flag to enable station voxels ("Station voxel support")
Scenarios can have live counters (and there's a new settings box for it)
There is a new material type - wood. There are also new models for trees. (this might be ME leakage).
SE will likely eventually get ME's inventory system per code comments:
// TODO: When this Inventory system is working well, remove it and use it as default for SE too
The engine constants for Pi, km, and g have been slightly adjusted (could have side effects for existing precise creations)