The gameplay is simple but it's very entertaining, I always find myself going back to this to check on my pets and play a little more.
Though I have to say, I wish the game wasn't so grindy. The in-game purchases are unnecessarily expensive, and considering how simple the features in this game are (and how repetitive they may feel after you've been some hours into the game), the effort to raise the funds you need to get these upgrades barely feel like they are rewarded at all. There are lots of stuff you can only buy with diamonds, and they're either WAY too expensive (like kitsunes that cost 700), or just straight up useless or not worth it (like SINGULAR tiny floor tiles, that are like.... 10+ each or something?) It feels like the developers are trying really hard to get you to spend your money, and that just doesn't feel very right to me.
But hey, at least the game is not pay-to-win. Most of the expensive purchases are simply luxury; you can try and save up for them if you want to, but even if you don't, it's not going to impact your experience.

If you got lots of free time, like animals, and are a fan of pet-caring games, then you should definitely give Pet idle a chance.