The game currently has 10 sets.
Promo Set (I call it a set since they are all placed together)
Set 1
Set 2
Set 3
Set 4
Set 5
Set 6
Set 7 (Last one released by Triking Games, although they had plans for several other sets)
Set 8 (Released by the Fans)
Set 9 (Released by the Fans)