Thanks for playing! The point was is that each enemy can change the zip-line route if you don't kill them before they do. So the enemy that comes from top to down is the one that makes the zipline have the same up-down pattern. The helicopter makes random patterns and the flying pink little guy (the helper) supposed to make it all flat again, so you probably don't want to hit it. But due to a game bug, it isn't working correctly. So hope that helps understand the intended mechanics!