The Slime Genotype:

Body - Same as a humanoid body, it can wear armour and clothing.
Nuclear Protrusion - This is the "Head" of the slime so helmets and such will be worn here.
Sensory Bulb - This would be the "Face" so masks and goggles will fit here.
Worn on membrane - This is the slime equivalent of a back so backpacks and other things will go here.
Pseudopod - These are essentially hands, you can equip either a weapon or glove type armour in each of these.

Slime do not have feet so you can't equip boots and you will bleed slime. The other four slots are self explanatory.

The Slime Subtypes:

Null - This is just the basic slime, it has no special abilities other than being able to consume things.

Unstable - This one is the same as the Null slime except when you enter a tile with any sort of liquid in it you will automatically take in the properties of the liquid. More on this later.

Stable - The same as Unstable except you have an ability so you can manually absorb liquid and therefore play in a way that suits you e.g. a lava slime.

The Slime Status mutation:

Examine the 'Slime Status' mutation in your mutations list to see amount of attribute points, mutation points, and mutations you have earned. This can also be accessed through the 'Slime Status' ability.

The Consume ability:

Also known as Engulf in-game, when you engulf a creature a few effects happen and these are...

Damage - The damage that the creature takes while being consumed is a random number in the range of your toughness divided by 2 to your toughness. These values are displayed in the Slime Status mutation.
Balanced Slime Damage - Damage is based on both your toughness, capped to 15, and how close to your current stat cap. Damage starts at 120%, and will reduce down to 20% as you reach your current stat gain level cap. Bud a new slimeling to shed stats to reduce your stat gain and increase Engulf damage.

Mutations - Once the creature has been consumed (killed) any mutations it had that you currently don't have will be given to you. You have the option to decline a mutation, which will prevent you from gaining that mutation via consumption in the future.

Attribute gain - When the creature is consumed if any of the creature's stats are greater than yours, you will gain a stat point in a random choice of one of those stats. Trivial to Average difficulty creatures only give a single stat point. Tough, Very Tough, and Impossible creatures give 2, 3, or 4 stat points, even if the creature does not have any stat higher than yours.
The amount you can earn is decided by your level, use the Slime Status ability or view the Slime Status mutation to see your current caps.

Mutation point gain - After consuming a number of creatures you will gain a mutation point to spend. Tougher creatures will accelerate the rate at which you gain a point. use the Slime Status ability or view the Slime Status mutation to see how many you can earn each level.

Attribute gain - Balanced slimes gain a portion of their SP each level through consuming other creatures. See the Slime Status Mutation to view current gains and caps at each level.

You will also have your thirst and hunger raised to Quenched and Sated.

A note about attribute / mutation point gain - You do not lose the potential for gains when leveling up. A counter does not reset, you still gain the same amount of points if you had hit the cap before leveling up. e.g. level 1 you have 4/10 points, if you then reach level 2 it will be 4/20.

The Evolution mutation:

When you touch a liquid and evolve either from the unstable slime's auto ability or the stable slime's manual ability, the liquid is checked to make sure you don't already have it then added to a list and from there if it is the first liquid then you will gain the spit ability which lets you spit whatever liquids you have absorbed so far. The other effects include giving you a Pseudopod relevant to the liquid and sometimes passive effects.

The spit ability works by checking each liquid that you have absorbed and spitting the combined liquids at a target or area. I believe that any creature caught by the liquid mix has those effects added to them, the same as if they walked through it naturally. So a combined spit of acid and asphalt would cause them to be stuck and take acid damage.

Each liquid you evolve will cause one of your pseudopods to gain that liquid's properties. If all 4 of your base pseudopods have been evolved, you will grow a new pseudopod for each new liquid.

Each pseudopod has the base stats of HitBonus="6" MaxStrengthBonus="99" BaseDamage="1d2" Skill="Cudgel" Stat="Strength".

Budding

Once a unstable or stable slime has evolved, you gain the option to Bud a Slimeling. Each time you bud a slimeling, one of your chosen liquids and a number of your stat points will be sacrificed and given to the new slimeling, which will follow you and fight for you. The stat point cost will be increased for each slimeling you have budded, up to a maximum of 55 stat points. If using the balanced slime genotype, each time you bud a new slime, your maximum attribute cap will be raised by 1.