the guided thing has an 'effective angle' of 45 degrees or something like that... when you see it coming towards you, for example, down-left, it will only be able to turn between full-left and full-down so you have to get out its angle range... to do this you must often run towards it... example.. if it's going down-left on you, going straight up will allow you to escape it if you can reach its vertical position before it's over you, because it will then only be able to turn full-left, and will not be able to climb up