The Smut Monkey's Passive income is small but not too small. The real issue is the cost of upgrading. It feels a bit too excessive. Because by the time you can afford it and multiple upgrades, the game's nearly over and you don't really need any other towers. At best you're producing between 7, 11, 14, 18, and 21 by the time Round 50 rolls around. I'm not sure if lowering the cost of the upgrade or increasing the payout would be better given how much the BDSM monkey cost.