Is Overwatch worth it?

It really depends on your taste. Are you into team based combat? Are you into teamwork?

I wouldn't recommend playing it for long but if you wanna give team based combat a try, paladins is the best free way to do so.

If you don't want to play ow though and are looking for steam alternatives, I would recommend Tf2 (duh because I'm that guy) or Gigantic which I wish I could play but I don't have 6gb ram)