I found a bug that may or may not be known to the BB support team. When a character or asset is on a path with the play mode set to Ping Pong, the image flips in a weird way. See the video for more details.
OK, FYI, we will be adding an option for flipping the object on the path in the final release (unfortunately it won't make BETA5). The current transition options are good for top-down and many other game types but not necessarily for a side scroller.