Not really I mean the fundamental skills to play FPS's are obviously present in both games but CoD is just a twitch shooter.

Halo requires fast reaction times as well, but unlike CoD you actually have to follow through with your shoots, you don't just instantly kill someone if you get the shot first. Also with shields you actually get a chance to retaliate if someone gets the jump on you first.

I don't see what skills are unique to CoD, I must be missing something?