I had to do the place quick trick for things to kick off correctly and found the red tower was the ony one that seemed to do anything for me (the last two didn't let me interact even with enough currency). I thought the motion and the way the stray bullets got carried along was nice, but I "won" even though a bunch of enemies got through in the last wave so not sure how well I actually did. During one playthrough attempt I also got stuck with the yellow tower attached to my cursor.