a good glitch for many towers: go over a spot to put the tower and then right click. then you can move the tower anywhere. just left click where you want it and it can go even on the track!
~Scrantoncity~
target priority is for all towers and it means that it will either attack the first balloon in its range or the last. So it doesnt matter for a tack but a catapult should always attack whichever way it shoots straight