Free to play, pay to win? A word on the microtransactions
Let me start by explaining one of the core mechanics of the game: construction and research. Progress in the game revolves mainly around villages and the research tree. For each building you construct in a village or research you complete, the time to do the next one increases. When you first start the game, construction/research is very quick, and you can feasibly be waiting around 1-2 minutes for your next thing to complete. However, it quickly reaches 10-15 minutes after playing for a short while. As there are limited things you can accomplish when you begin the game, there isn't a whole lot else you can be doing while waiting for the next building/research. This means you really do start to notice the wait time.
I described the building/research time in such detail because I wanted to drive home the importance of the PREMIUM TOKEN. The only real-money transaction that (IMO) makes a large difference is the premium token. It enables building and research queues, meaning you can queue up to 5 buildings & research at a time, as well as have other tasks completed you for automatically. To keep a consistent token on, it would only come to around a few dollars a month. While it does significantly accelerate your progress, you can still grow your Kingdom at a decent rate without it (like I did).
Personally, I have over 500 hours on the game. Not all of them were spent playing, a lot were from leaving it open between checks. Most of my playtime was free, but I did pay for some premium tokens because I was really enjoying it. Just to be clear, this game is not one where you can play for hours on end, fully immersed. This game is more of a “log in, complete some things, log off and come back later.” If you like this style of game (real-time, empire builder), I would recommend it. However, just be warned that in order to make significant progress, you will need to pour in a lot of time (and perhaps a little money!). It is not, however, totally pay to win.