Our family used this as the basis for our family worship/devotional time after supper 5 days a week in 2014-2015. Machowski walks through the unfolding story of the OT by boiling down the episodes into 5 day long examinations (78 Weeks in total). The first day of the week starts off introducing the particular story/episode with some concrete object lesson which is usually effective to grab the children's attention and engage their thinking and the author uses that to transition into the biblical story and the explanation of it for the next 5 days of devotionals/teaching times. Thankfully the object lessons usually involve minimal prep so it doesn't become onerous for parents. Each of the 5 days readings from Scripture are accompanied by a brief explanation of the text and the main themes highlighted are usually man's sin and need of God and God's gracious and faithful relationship with his people. Day three's reading takes a break from the main text and looks at how the week's story points forward to Jesus, often incorporating a NT reading. The fifth day's reading looks at either a Psalm or a Prophet to see how it points forward to Christ or speaks of salvation through Christ. The Psalm or prophetic reading chosen often highlights some theme or event from that week's story as well. After the readings and the explanations, there are usually 3 questions to help with comprehension and basic listening. There is also a question for the kids to ask their parents about a time where they may have done something or witnessed something related to the main focus of that day's reading. Sometimes also children are encouraged to recall a time when they committed a particular sin that is similar in nature to the sin a character in the story committed (more on this below). Each day's episode ends in a prompt to pray for or thank God for something themed according to that day's reading.
I found that Machowski's discussion of the OT events or episodes sometimes missed some very important observations, either in the historical context, or in the way those events pointed forward to Christ. Obviously this is to be expected when a book is structured to be a 10-15 minute devotional or teaching time...you're going to miss a lot. However, sometimes it seemed to me it was a central thing that was missed, passed over for a point of lesser importance. But in fairness this didn't happen very often so this wasn't really a drawback.
I also found that Machowski over simplified salvation and boiled it down to believing in Jesus, that his death on the cross forgives our sins so that we will go to be with him in heaven when we die. Not that he's wrong, just that it makes much of the discussion of salvation future-oriented (going to heaven instead of hell when we die) and leaves the present Christian experience of union with Christ or walking as God's children here and now often unexplored. Again, what he emphasizes is obviously of prime importance, but it does seem to focus on one aspect of the cross and leaves many significant aspects of salvation unexplored. Perhaps that is because this is meant to be aimed at the younger end of the spectrum, but I found that the point was all to often exclusively about "going to heaven to be with Jesus when we die". However, that is where a conscientious parent can step up and broaden or deepen the discussion depending on the ages of the children one is working through this with. So again, not a glaring weakness, just a heads-up to parents. The salvation we have through Christ's life, death, resurrection and reign is so rich, it would be good to bring in a more fulsome perspective on this in your discussion as a family.
Now, about the author's encouraging children to think of a time when they sinned in a way similar to the character(s) in the story, or encouraging parents to recall a time when the children disobeyed in a particular way (see above) - while I understand that this is meant to both show our own sinfulness and need of Christ, as well as show that we are not so different from the flawed characters of Scripture, I would encourage parents to do this wisely, cautiously and sparingly, if at all. Scripture presents us with a vision of God as one who forgives and then doesn't impute our sin and guilt to us any more, who removes our sins as far as east from west, and we are likewise called to forgive and love in such a way that keeps no record of wrongs. What we don't want to do as parents is to repeatedly bring up our children's past sins in teaching times when we are focusing on God's salvation, forgiveness and grace to us through Christ Jesus. Of course to teach this we must talk about our sin and our children's sin, and sin is only theoretical if we never actually speak of specific ways that we sin, actual sins we sometimes commit. However, I would caution parents about bringing up past sins that have already been disciplined for, discussed and forgiven. Sometimes doing that can defeat or counter act the very lesson of salvation, grace and forgiveness we are attempting to teach.
Overall however, I commend this book warmly.