After reading this: "UPDATE 2: Okay – I’ve added some extra checks that should help to avoid some of the bugs. In addition to that, I’ve added a “Fail Safe” button. If the game bugs out, or you have one troop hitting you out of range, or enemies stuck, click the CALENDAR beside the WAVE COUNTER. That button will cause the enemies to all find a new path, and should fix those errors if they occur during your game!" i tried to multi-click the calendar buttom and guess what??? enemies will came one by one, LOL, nice cheat I found. Click + if you like it