To be able to answer this question, a definition of goodness is required, perhaps as a mathematical function of a given world, such that you can make objective comparisons of the form:
- Goodness (world1) > Goodness (world2)
- Goodness (world1) < Goodness (world2)
- Goodness (world1) = Goodness (world2)
Furthermore, we need a very precise definition of what a world is, and as eques correctly pointed out in his answer, we need to make sure that we only consider counterfactual worlds that are logically possible, free of inconsistencies, absurdities or contradictions. And if you are a Molinist, you might also want to restrict your options to worlds that are feasible. William Lane Craig talks about the distinction between possible and feasible worlds in this article:
God’s middle knowledge is His knowledge of all contingently true conditional propositions in the subjunctive mood, including propositions about creaturely free actions. For example, logically prior to His creative decree, God knew that if Peter were in circumstances C, he would freely deny Christ three times. Such subjunctive conditionals are often called counterfactuals. These counterfactuals serve to delimit the range of possible worlds to worlds which are feasible for God to actualize. For example, there is an intrinsically possible world in which Peter freely affirms Christ in precisely the same circumstances in which he in fact denied him; but given the counterfactual truth that if Peter were in precisely those circumstances he would freely deny Christ, then the possible world in which Peter freely affirms Christ in those circumstances is not feasible for God. God could force Peter to affirm Christ in those circumstances, but then his confession would not be free. By means of His middle knowledge, God knows what is the proper subset of possible worlds which are feasible for Him, given the counterfactuals that are true.
God then decrees to create certain free creatures in certain circumstances and, thus, on the basis of his middle knowledge and His knowledge of His own decree, God has foreknowledge of everything that will happen (His free knowledge). In that way, He knows, simply on the basis of His own internal states and without any need of any sort of perception of the external world, that Peter will freely deny Christ three times.
So there are worlds which are intrinsically possible but which God, given the counterfactuals that happen to be true, is not capable of actualizing and which are therefore, in Flint’s terminology, infeasible for God. Notice that because counterfactuals of creaturely freedom are contingently true, which worlds are feasible for God and which are infeasible is also a contingent matter. It all depends on how creatures would freely behave in various circumstances, which is beyond God’s control.
Moreover, the question seems to assume that God can be viewed as some sort of utilitarian, in the sense that among all possible worlds, He decided to create a specific world that maximizes a Goodness (or Utility) function. As if He was solving a utility maximization/optimization problem when He decided to create this world. I personally don't take any issues with this view, but viewing God as a utilitarian is controversial among Christians. I know this as I've had my fair share of facing firsthand this controversy in previous questions I've asked: What are counterexamples to the position that Christian morality is ultimately utilitarian (i.e., that God is utilitarian)?, According to Christians who believe that God is a utilitarian, why is homosexuality suboptimal?. Even Molinism itself is far from being the dominant view among Christians and is not free of criticism.
So, my answer to the question is that the question as currently stated is ambiguous and therefore unanswerable, as the question offers no precise definition of Goodness nor a specific alternative world that would be judged to be better (under that hypothetical definition of Goodness). However, if you allow answerers to fill in the blanks of your question with their own assumptions, a Molinist for example could say that if God did in fact create the best of all possible/feasible worlds, then it would logically follow that there is no other possible/feasible world that God could have created that would have been better than this one (according to God's standard of goodness, which is a mystery to us), and therefore your imagined world is either impossible, unfeasible or wrongly judged/evaluated (from God's perspective).
You might also be interested in taking a look at this recent question I asked: Do Christians believe that God chose to create the "best possible world" among multiple/infinite alternatives, by maximizing a "Goodness" function?