In the start you can choose type of a soldier, change the color and do many other great things with it. After you chose your soldier, you can play two different modes. Challenge mode, and Campaign mode.
Both of them are very good, so it is up to you which of them you will play.You need to explore mission by mission to see the whole picture of this awesome game.
I think you also want to know about subject and interface of the game. Strike force heroes has one of the greatest graphics in flash games industry, and I am sure you will be excited when you see it with your own eyes. You are a boss of group of special forces, who are the best soldiers in the army and you try to destroy terrorists all over the world. You may asked to take operation in any place, so do not be surprised if you will fight with terrorist in the air, on the wings of the hijacked airplane. I think it is enough to explain you how great strike force heroes are. Now you should play to feel all the above mentioned.