is there Single Player gameplay here as well ?

No. Multiplayer only. However, you can play with bots, if you really want to.

and how good are those ?

Very good in my opinion. Of course human players are still prefered but if you don't know that you are playing bots, it should take a while for you to notice.

No wait, you'll notice it immediatly because the bots actual work in a team with you and do what you order them to do. Something human players will never even think of doing :).