Slave Matrix is a monster girl slave/breeding focused game made by Auto Eden, where you get to mix and match different species of monsters to create mixed breeds. It gets surprisingly detailed when you throw in different traits, varying body sizes, magical mutations, blessings and so on.
At the start of the game, you're tasked to pay off a debt and are locked with just two species, lamias and harpies. They both have a few different subspecies peppered in them, but until you're debt free, those are your only options. You can also buy toys to use on your slaves, thus spicing up the training a little.
If the mating is too complicated for you, or if you feel like giving a more simpler approcach a try, you can turn on simple mating in the Config.ini.
