As long as you have more than one kitten, you can still breed between them. This mechanic still works, even if you're playing alone. And the prices (AFAIK) are

As long as you have more than one kitten, you can still breed between them. This mechanic still works, even if you're playing alone. And the prices (AFAIK) are also totally handled with smart contracts, so even if it's just you, you can still claim the price.