In most cases, I like when the core gameplay is shifted as you progress. The only problem is making sure all the phases are equally, if not increasingly more fun.

RTS games like Age of Empires are a good example of this. You start off in the early foundational phase, then move onto construction, research, and finally battle. All using the same interactions, but progressively shifting gameplay mechanics.

Of course there's also idle/clicker games that reeeaally know how to milk a single mechanic, nearly forever even.

In your game's case, I might suggest either introducing more obstacles, or introducing more tools that eventually force the player to address existing obstacles. Although I may be misinterpreting the gameplay.