Most students I have taught in this last decade will probably remember some version of this graph (trust me, it didn't look this nice when I drew it with stick figures). You might have seen me substitute Learning for Performance because there is strong brain-science evidence that pressure or stress improves the learning process ... up to a point. And it is exactly that "point" to which I-L-Xs like OneDay are designed to drive each individual player; to the highest possible level of learning and application of knowledge – at the student's own speed.
My son, Adam, was born with Down Syndrome, but even as a young teen, he could regularly and thoroughly trounce me on every videogame he owned. Granted, it probably took him three times as long as a person with normal IQ to learn to play the game well, but once he did, he mastered it. Can you think of any other time human history that a kid with Down Syndrome could beat an able-bodied, PhD diploma-boasting adult who was trying his damned hardest to win?
Well, my learnings from those experiences with my son are built into these games. Students can play I-L-Xs over and over again as many times as they need to master the subject area and reach their zenith of learning and performance.