CommanderCody,
You can play the German side you just go to another site to do so. I did not rate the game a 2/5 because of how easy it was I rated it that because of the game as a whole. I should have made it clear that the statement of it being to easy was not the reason for the rating.
This game takes place in 1917 so the German army did have tanks at this time. It was called the Schwerer Kampfwagen A7V. If the game was in 1916 then only the British would have tanks. The A7V was first demonstrated in the spring of 1917 not 1918. There were 100 of them made by the end of 1917. It did not gain a large roll in the war until 1918.