User blog comment:Frogo510/What did Past COD games have that brought innovation to the series?/@comment-32237267-20120806020442

Call of Duty 4: Modern Warfare had a lot of major changes:

1.) Removed vehicles,

2.) Added killstreaks

3.) Added Attachments

4.) Added Create-a-Class

5.) Added Equipment

6.) Added Camouflages

7.) Brought the series out of World War II

8.) Removed the ability of having two primaries and one secondary

9.) Added Arcade Mode

10.) More multiplayer game modes

11.) Instead of playing as 3 or 4 nationalities in singleplayer, you only play 2.

12.) Had actual antagonists (The Four Horsemen)

13.) Added Perks

14.) Added a Ranking System

15.) Added Challenges

16.) Collectible Intel

17.) In-Game Cheats

18.) You have a knife :D

19.) Playable Characters died in singleplayer

20.) Smaller maps