I see comments about selling/moving towers during a level. I find the recovery lag and the recharge timer too long to risk it. Only on the two-path level, the last level and one other did I dare even try it. My timid solution was to come back to hard levels after I'd upgraded enough. So the game IS very well balanced. :D
TO GET CREDIT FOR the Badge of the Day - Return to your profile page. As @Meyismyname suggested, that is all I had to do. I suspect that game progress is stored locally but badge credit is kept by Kongregate.
This game does NOT work on my Chromebook. It ignores the keyboard for several seconds so I can't move, then zips across the map. I have no idea what keyboard settings might work.
FYI - After a tower kills an enemy, it won't see ghosts that's are flying over towers. When the ghost passes over open floor it can target it. Also, if a tower is built where an enemy is already in range it may fail to see it.
Your nanos that are traveling will eliminate red nanos they run into - so as soon as you're producing more than them: select several of your cells and click once on the four weakest cells, select other cells and repeat quickly. Send them to your own depleted cells too . Fill the screen with nanos traveling in every direction and the red nanos will never make it to another cell.
Thanks for the tips Torbax and Darknut79! For the "Show us your ..." badge score is key so I went for combos (swing→bees→bees→fling). I set the path upward so I could use both swing traps right off. Here's the layout, I added blue trigger links: !http://imgur.com/langRCy!
Took me a few tries at the build/upgrade order to keep some of the captain waves from getting thru
Finally beat level 20 - every light green and control the close one on the left. This game would be sooo awesome if each light was labeled with a key that toggled it.
FYI: use A & D to leave your castle, W to enter castles (yours, white or enemy! *avoid flyers and archers*)
If you take enemy castle and leave, their archers can't shoot thru it until a unit takes it back.
It took me several tries to beat the final level. I took over a white tower near the enemy's castle and wiped out his first wave. That let my horsemen grab his flag. Then I just had to focus on any units that could hurt the flag bearer - archers and the flyers. I also threw heal waves at him. They returned with the flag before that pesky giant could show up and kill me!