Funny story, I watched this level in a YouTube channel it was tagged as "Hard" (link), so I was intimidated by it from the get-go! However, after playing it, I think it wasn't so hard (definitively easier compared with some of your more recent levels...) and I actually felt it was kind of short! The mechanism is great, and although the level can be completed quickly, it's a lot of fun figuring out how to get from one point to another. Excellent! Thanks!
Review and Rating: Design: 4.0 = If it wasn't for the infinite rolling mechanism, I would rate it lower. It's less appealing compared to the other levels. Gameplay: 3.8 = It's nice to roam around with the balls running. However, the excitement went hanging as I unexpectedly finished the game fast. The potential of the mechanism was not fully utilized. Replayability: 3.5 = I would only play it once but if you want to enjoy the mechanism then you could go for a couple more. Difficulty: Normal Final Verdict: 3.76 = A good game that fell short. A nice level for intermediate players.
This is certainly a perpetual motion machine. It's oddly satisfying to observe how the balls return to where they come from.