Also if you exit the tower, your banked gems are added to your total score. I just got the 50,000 trophy by ending at a total of 31000 because I banked 20000.
410710. I was trying to be safe in a corner, but then accidently ran into something :(. Might have had a higher multiplier throughout if I took more risks.
The scoring seems weird until you realize that it's based off scrabble. Rarer letters do more damage. If you know good words, you shouldn't be using all level 1 letters.
Really i thought the hydra was worse than the tank. Tank is really easy, just keep the guy sealed, defend shoop da woop, keep protect/barrier/regen up, and only attack the tank. I don't think I used an item at all...
 "Obey the Game"){kind=icon}
 "Tower of Greed"){kind=icon}
 "Blocks With Letters On"){kind=icon}
 "Luminara"){kind=icon}
 "Polygonal Fury"){kind=icon}
 "Frantic 2"){kind=icon}
 "Hedgehog Launch 2"){kind=icon}
 "Clockwords: Prelude"){kind=icon}
 "Frontier"){kind=icon}
 "Bloons Tower Defense 3"){kind=icon}
 "Epic Battle Fantasy 2"){kind=icon}
 "Zilch"){kind=icon}
 "Crush the Castle Players Pack"){kind=icon}