Are you asking from the perspective of technicalities of implementing or the ramifications of the design? Either way, the answer to your question is "yes".

From the technical side of things, generally speaking you just find the hooks in your code that are responding to your achievement events and put in your stat tracking code there. You might have to add some new things if you're tracking things that aren't exactly discrete events that area already happening in the game (for example: X amount of hours played).

From the design side of things, well, adding achievements are extrinsic motivators and don't really play too much into the core gameplay loop, except for people who want to seek them out. So they're pretty safe regardless.

Are you asking from the perspective of technicalities of implementing or the ramifications of the design? Either way, the answer to your question is "yes".

From the technical side of things, generally speaking you just find the hooks in your code that are responding to your achievement events and put in your stat tracking code there. You might have to add some new things if you're tracking things that aren't exactly discrete events that are already happening in the game (for example: X amount of hours played).

From the design side of things, well, achievements are extrinsic motivators and adding them doesn't really play too much into the core gameplay loop, except for people who want to seek them out. So they're pretty safe regardless.