Well, I had a thought of a few mutations for the game..
I'd love suggestions for them and maybe some critique.
All of these mutations are based off real mutations.
Sorry if any of these have been suggested before.
Here they are:

Radial Hypoplasia
Cats with an additional deformity such as spina bifida; cats with peculiarly short front legs due to radial hypoplasia, There are also kittens born with straightened or twisted hind legs due to cramping in the womb.
~So basically, any lion{ess} born with the mutation would be basically disabled and like blind lions- unable to do anything. It would only affect a lion{ess} that was born in a litter in four cubs, and the mutation would be rare-very rare.
Lethal: Yes, lioness/lion would die at 3-4 months

Cutaneous Asthenia
Extra limbs that just wound up at the right place, The cats actually can’t fly, and outside of some instances where it’s simply a matter of matted fur, there have been cases on a genetic level at well.
~Basically, the "winged" cats mutation. It would be common, seeing more and more "winged" cats are showing up on the Earth. The mutation would do nothing to the gameplay.
Lethal; No.

Holoprosencephaly
A strange little piglet with the face of a monkey was born in a small village in China. Most of the family was terrified of the piglet but it soon became a bit of a tourist attraction, not to mention the fact that their young son took a liking to the pig as a pet. The piglet’s condition is thought to be a result of a genetic defect known as holoprosencephaly. This condition can cause cyclopia, which may explain why the pig’s eyes are so close together.
~The cub would be born with a monkey like face, and it's eyes close together, but not cyclopia. This would be a very rare mutation.
Lethal: Yes.

Three Eyed
In a strange instance of life imitating art, here we have a real-life genetic mutation that was the pulled right out of an episode of the Simpson, in which Bart catches a three-eyed fish dubbed “Blinky” in the waters surrounding the Springfield Nuclear Power Plant. A scandal ensues. Swap Bart with a fisherman named Julian Zmutt and swap a nuclear power plant in Springfield with a nuclear power plant in Argentina, and the story is essentially the same.
~Pretty self explanatory but the lion{ess} would have three eyes. The third would be located on their forehead, and would be useless. It would look like a blind eye, rolled backwards slightly or something like that. The lion{ess} would not be affected in anyway
Lethal: No.

Cleft Lip
Cleft lip (often referred to incorrectly as a “hair lip” or more appropriately as palatoschisis or congenital oronasal fistula).
~The cub's top lip would be missing or shrunken in, showing it's top front teeth. This would affect the cub, as it would not be able to suckle/eat.
Lethal: Yes, would die at 5 months.
{Suggested by Cairo c:}