Thanks for playing! While playtesting this game, I actually found 6 different viable strategies to clear it. One of them is clearing it using only the $20 ranged units. If you intentionally sacrifice your base and let only one enemy ranged monkey remain, then summon your ranged bananas, I set it up so the enemy projectiles fly right over their heads. That way you can stack 6 or more ranged bananas, and if you then keep producing $10 melee bananas, you can clear it on your first try fairly easily. It does require a bit of luck though.
Really glad you enjoyed the game! I'll keep thinking about the balance and definitely take it into account for my next project. Thanks again for the feedback!