Was a little confused, but once I figured it out it was playable. I didn't immediately understand that there was a limit to the amount of objects I could build. The paths didn't seem to matter as the ai would just take their predetermined route regardless of what visibly looked like their path.
Also noticed that your score just increasingly goes up the more you play - so I wasn't really sure of what was the high score that I'm chasing as it'll just add to my previous score.
Good effort though!