Found a niche bug; apparently, if you get a high enough happy score (I'd assume 1b), the happy score resets to 0. I had the grandma and baby far beyond 100 million, and then at some point, they reset. Luckily, my circus didn't reset.
Looking at balancing I feel like alien has some really powerful relics. I'm not saying alien should be nerfed, but I think it might be worth buffing some of the other types. I find the friends in other types to be really unique but always feel the relics need a bit more oomph.
I found a couple of things a little hard to understand and I'm really surprised so many stat improvements are permanent across rounds. The scaling seems fun and I felt like I could always find something to upgrade my set.