It's okay, but it wobbles even when I have the biggest base I can possibly have. Just 10 away from the impossible badge and one purple figure falls off. :(
I got the hard badge using 10-ish half-upgraded cannons, 10-ish half-upgraded tack shooters, and 1 fully upgraded super monkey. 4.8/5 (-.2 because I wasted 2 hours on this badge)
 "99 Bricks"){kind=icon}
 "Bloons Tower Defense 3"){kind=icon}