serious bugs..game does not stop and the color doesn't even change. Even those things don't die and some just fly out of the screen. I like the game concept though...
For Challenge 4, this is what i know:
Shield goes to destination and straight beyond. sword tends to get close to the dragon. If shield is too close, the dragon does not bother to shoot at it. there is a good chance for you to attack your shield accidentally. Controlling 2 bots at once is quite difficult.
I noticed that shield moves almost straight past the specific location. It's like the shield is thrown at that direction. This could be a clue to the solution XD.