The stage K9 is too damn hard at the current level you're at when you reach it, forcing you to go back and grind the hell out of the earlier levels, scraping together every last bit of exp that you can so you can finally stand a chance.
The only downside is that a lot of times, you're forced to go through a certain map that you really don't want to do in order to progress. For example, I really dislike the maps with big open spaces, but I'm forced to go through field M10 in order to get anywhere.
Oh god, I remember when I went through the Fire Temple before the Water temple sheerly by accident. XD I'm not complaining that I wasn't told where to go, I'm actually happy that I went the "wrong" way, because it made me so overpowered for the rest of the game. But the "World's Saviors".... oh god were they tough. -keeps laughing-
I've earned 2 of the listed badges, but apparently, Kongregate is being a dick and won't recognize them. This also happened on BTD4, with the Badge of the Day. I didn't get my points, so apparently, I'm never going to see those GameStop Power Up reward points that I earned.
There's a big problem with one of the missions. It says to squash a gummy carrying an item while wearing a propeller hat, yet it's impossible to do so, since all item carrying gummies are on the ground, and the propeller hat only pushes you up. You CAN'T squash any item-carrying gummies while wearing the propeller hat. It's impossible!
 "Road of the Dead 2"){kind=icon}
 "GemCraft Labyrinth"){kind=icon}
 "Ghost Hacker 2"){kind=icon}
 "Epic Battle Fantasy 4"){kind=icon}
 "Glean"){kind=icon}
 "Paladog"){kind=icon}
 "MARDEK RPG: Chapter 3"){kind=icon}
 "Zomgies 2"){kind=icon}
 "Epic Combo!"){kind=icon}
 "Reincarnation: Out to Sea You Die"){kind=icon}
 "Crystal Saga"){kind=icon}
 "Villainous"){kind=icon}
 "Burrito Bison Revenge"){kind=icon}