Damn, this is a hell of a thing to have turned out in a month - I'm always weak for a good sandbox management, and this has the bones of a great one. It was quite fun to realise that the himbofication machines actually endeared more people to go to the gym - I figured it would be the opposite, and it was a fun eureka moment.
The controls were a little funky - my first playthrough I had to restart since I managed to double-layer a NPC's invite menu, and I also ran into the 115% success rate, mouse focus and desynced animations that've been noted as well. It was also a little annoying not having any visual way to tell who had joined my gym or not - near the end I was running up to whatever new NPC had spawned like some deranged street side salesperson, only to find they were already part of my gym.
I definitely was wishing there was more to play with though once I hit that final 2500 upgrade , which I think is always a great sign with a management game. (And the cover art for this? Fantastic!)