So progression is locked to:
1) Buy free Foxen home
2) Have wild sex with male/female foxen to tame them
3) Milk the foxen for resources
4) Sell for currency to buy milk/semen
Do you really think so?
Let's see:
1. Talk to Fern, give her your fluids like 10 or 20 times in a row, each time earning a few shiny (Note: I strongly suggest you to use the cheat code "infinite lust" before starting to play; otherwise, everything in this game becomes a total waste of time).
2. Visit Cassie, obtain the Fox house for free, then buy the Wulvarg house for 20 shiny and the Risu house for 30 shiny (if you have collected that much).
3. Let Fern milk you for a few more shiny.
4. Visit the semen store to purchase a few doses of Thriae semen and Titan semen.
5. Go to Lustwood, have sex with foxes to catch a few of them.
6. Since the wolves are higher level than foxes, it may take a while before you catch up with them. So, to make it quick, use Titan semen to catch female Vulwargs (male wolves prefer fox milk, which should not be a problem to obtain).
7. Go down the river, find the Risu cave, use Thriae semen to catch a few bunnies.
So now, you have 3 barns with 3 species of Nephs to start with. Milk them and sell the fluids to amass enough shiny to buy the rest of the barns.
In the meantime, start doing the quest chain to unlock all the gates.
But if you don't want to bother with it, just enter the code
imma lazy sack
and enjoy the sandbox!