you need to flip midair in second level and third takes time and practice, currently working on fourth, there are two cubes below the starting platform that you need to get past the start, after that you need to flip grab a cube then reflip doing a areal 180 and landing on the finish platform, still working on that one :P
its a great game with shortcuts (you can climb up a skyscraper for an advantage), ive only found a few physics glitches (ive gone flying for no reason)