score:5
When we put several passages together to get a fuller picture, we can see in what sense "overlook" is being used. Consider the following two verses, which are similar in scope (from the NET translation):
Rom. 3:25
God publicly displayed him at his death as the mercy seat accessible through faith. This was to demonstrate his righteousness, because God in his forbearance had passed over the sins previously committed.
Acts 14:16
In past generations he allowed all the nations to go their own ways
I'll also add your passage for completeness:
Acts 17:30
Therefore, although God has overlooked such times of ignorance, he now commands all people everywhere to repent,
From these passages we see that overlook is being used in the sense of patience on God's part. See the words "forebearance" and "allowed." God still executed wrath on the nations; as we see in Rom. 1:18ff, God showed His wrath in times past by letting the nations do what they want ("God gave them over"), and allowing them to suffer the consequences of life without God. The nations are culpable because creation declares a Creator, and they willingly turned away from Him, and their consciences will judge them for they did (Rom. 2:14-15). Thus, the ignorant people won't get a free pass -- they do know what sin is.
So "overlook" is not being used in the sense of turning a blind eye to sin. The three passages taken together seem to indicate that God held back His fullest wrath and showed mercy and grace, anticipating the cross to come. Now with the cross demonstrating God dealing with sin, God commands all to repent. The people have creation to help detect a Creator, but now with the written Word of God and the cross, we can see Him as one who decisively deals with sin.