should I get this game? I heard it is great..but can you still get all the achievements? Do enough people still play?
Yes, you can still get all the achievements. I really enjoyed playing the campaign and getting all the achievements again.

People still play the game, but not many.

I’d say it’s worth it.
Never gonna tell someone not to buy a game! But seriously, it's a lot of fun and worth the purchase
I feel that it would be worth it I like the strategy theme that the gameplay is,its fun I love playing it
Not sure if you’re asking about the original or Definitive Edition, but I’d highly recommend the original. The DE has a ton of issues like inconsistent framerate, weird physics, and terrible networking. Save yourself the hassle and get the original in case you haven’t played it yet. If you have played the original and are prepared to deal with the problems I mentioned above, the DE is a cool way to experience the game again with some cleaner graphics.