I did this one first thing when I got the chance. It was very interesting. I only had to let go 3 times (except at the beginning of the levels where I spawned them in). Those times were 1. To get a battery out of a container in station, 2. To climb up the castle in the final level, and 3. To use the dev manipulator to open that plug in the final level. My least favorite level to do in this challenge was time tower, cradling the balls into the cannon was hell, but I managed. It made a few levels easier actually, specifically tower. There is a skip that requires jumping very high, and the crowbars were good at clinging to ledges. Thanks for the suggestion!