tips:
yellow are most valuable as they can change color and give you life
blue are next since they can double what you can get
black is useless.
So basically in that order, you should gather yellow, blue, and leave black, once they form a huge patch just change their color and continue on. Let just say that 100K isn't very easy since they don't give much points for kill, and killing 10+ of the same color doesn't happen alot.
level 33, the key block is the top small blue block, go down, left, up, right, hit the small top blue block, go right, get the blue box to be solid again, go left, up right.
The way to beat the boss is not on creatures but on arrows, stall his ass with noobs that doesn't cost mana + angels (because they last long). and start shooting the boss with arrows (all 4 kind). Should be able to kill him even before he touch your castle.
 "Shopping Cart Hero"){kind=icon}
 "Bloody Fun Day"){kind=icon}
 "Mushroom Revolution"){kind=icon}
 "Square2Ball"){kind=icon}
 "Bloons Tower Defense 3"){kind=icon}
 "Epic war"){kind=icon}
 "Protector: Reclaiming the Throne"){kind=icon}