I'm not really sure what its gameplay purpose is. I guess it's the only real source of "difficulty" in the game? If you get tired of it and stop doing it, eventually your happiness tanks. Than you clean up the jizz everywhere and are diligent about it for an honestly pretty brief amount of time, and it bounces right back up. Otherwise you'd need to run out of food, which is very easy to not do. The lack of a Jizz Janitor is the nest's greatest threat.
You can also theoretically fail raids, though since you know if it'll be a success or not before you send there's not really much challenge there. The only challenge about raiding is getting lazy because replenishing the number of gobbos in the raiding party when they attrition is a few clicks more than is convenient (come on, at least put me at their current number when I click to edit how many gobs are in the raiding party instead of setting it right back at 0), and eventually clicking the send raid button without realizing that because you didn't replenish the gobbo numbers, you're under the required raid strength for either the frontline or the backline. And of course you can't recall them when you realize your mistake, you can only watch as the 30 backline gobbos tragically march off to their certain death, never to jizz on the wall directly next to a woman again. I don't understand why you're even allowed to send the raid if you don't meet the strength requirements.
It's a porn game so it's fine that it's basically just a number go up simulator without any real challenge (though this is in pretty stark contrast to previous game Herione Conquest). I'm more bugged that the sources of challenge that are there, are really just annoyances/inconveniences that get in the way of the porn. Neither Jizz Janitor nor Remember To Click 8 Times Before Raiding Simulator really add to the experience in any way.
