I'm not exactly sure how many years. I'd say five, but looking at the age of the game, perhaps it was only four. Either way, I remember being obsessed with it once. I recently got really into it again, but even in between, I kept it on my ipad and would occasionally open it to buy some businesses. I can see how it can be dull, repetitive, and boring, but I personally have never felt that. Events are so fun, with the goals to reach towards and competing with other people. You get rewards either way, just better rewards in higher places lol. (And btw, the people seem like robots sometimes but they aren't. Which is cool) I've read about how Mars is easier than Moon which is easier than Earth, and since I've hyperinvested in Earth already, my goal is to finish Earth first hehe. There are ads, but never unprompted. It gives you a choice, and the rewards are usually just good enough that you want to watch it, but that they're skippable if you prefer. They even have hilarious names for upgrades! Numerous puns and references, it really adds so much more interest and entertainment. I always love devs with a sense of humor. My point is, with three planets to keep you busy, as well as events (usually a 15 hour gap between each, just enough to rest lol), and amazing playability even with nothing spent (I actually prefer free to play, it means you've earned everything you have lol), I can see myself playing this game for years to come.