When I first started Ovipets, it was exactly what I was looking for, a complex breeding game using Mendelian genetics. This means that traits can be recessive, and while some parental traits might not show up in direct offspring, they are carried and can show up in "grandchildren".
Ovipets is a Facebook game, and if you are a daily Facebook user like myself, this can be convenient. When creating an account, you open up a tutorial which helps you get started. The tutorial can be left by clicking the upper right X, and it can be re-opened at any time as needed. The interface uses tabs which can be labeled to organize your pets. You are also given 100 credits which can be used towards research in your lab. More credits can be earned by turning your neighbor's eggs, or by purchasing Facebook credits.
My first 100 credits took me pretty far. I focused on researching dragons, and I was able to get to Level 4 without researching specific genes. As Level 5 is reserved for those who only purchased through Facebook credits, the few credits I had leftover went into specific traits that I wanted, such as wings. Earning credits through turning eggs requires patience and a lot of clicking (something I have to pace myself with as I have carpal tunnel) as finding them is sporadic. I haven't done specific tests, but I estimate that the ratio of finding a credit is 1 out of 15 to 20 clicks. There are some days where I feel like I'll turn over 50 or more before finding anything, and then there are times when I'll find 3 in under 10 clicks. I can usually find enough to splice the genes in about 1 egg a day, and as dragons are the more expensive creatures to mutate, that's not bad.
I will probably buy a $5 Facebook credit card to fund some extra research and splice some eggs all at once. $5 will get you 200 Ovipets credits. Since my first 100 credits went pretty far, I feel like this is a fair price. Buying credits for only one time will also give you access to research Level 5 and research traits specific to that level.
Breeding is very robust with five color options to keep in mind as you try to pair up for the perfect offspring. Dominant and recessive genes must also be kept in mind, especially since two parents with the same recessive trait can produce offspring with that trait as dominant. Any trait can show up whether you have researched it or not. Research only gives you the ability to splice the genes in an egg, it does not dictate breeding outcomes. Simply owning a pet with certain traits make those traits breedable, so trading with neighbors, or grabbing pets off the adoption center is going to be a primary activity.
Credits can also be used to generate a new pet with specific colors. I generated a white dragon with yellow markings. The color scale is easy to customize to get exactly what you want. This is useful if you want to breed for a specific color.
Here is an example of genetic engineering trees
The artwork is crisp and cartoony with flat colors. The style is slightly cutsey, but not chibi or anime. It is definitely unique and pleasant. I prefer the wolves and dragons, and have shied away from some of the other animal types, partly to not over-extend myself, and partly because I don't prefer the look. I feel there is something endearing for almost every taste, and it will not be difficult to find a niche pet type that one prefers.
As it stands, Ovipets has no extra games or content outside of the breeding and egg hatching. Robust as the breeding system is, I don't feel it needs more content other than offering more traits to research. I have lost hours to this, searching through my pets to combine the right pairs, or lurking the adoption center to snatch pets with new traits or richer colors. If breeding is one of the things you enjoy in any pet game, I would recommend trying Ovipets. If you do, don't hestitate to friend me in-game http://ovipets.com
Oh yeah, you can friend other players in-game without friending them on Facebook, truly wonderful if you don't want to spam your account with people you don't know. Friends who do play are automatically neighbors in-game.