How hard would it be to implement some rudimentary graphs showing the production rate over the last n hours for each swarm member? Would be interesting to see the growth curves vs. the sudden dips caused by purchasing an upgrade.
Great game, but a couple of points, some of which are well established, are detracting from my overall score. Firstly, it's too grindy. 3 for 1 on level replays makes it too time consuming to try out all upgrades. Secondly, can we have the option to "drop" a super powerup? More often than not it's less powerful than my standard Monkey, and results in me missing bloons I would have otherwise popped.
Other than that, polished and fun - great work!
Is there a maximum amount of gold you can get from each level? I noticed it stopped accruing after a certain amount of time. Also, after defeating the boss at the end of stage 2 I was left with a steady trickle of enemies spawning from off screen with no way of completing the level. Other than that, fantastic game!