Thank you, TittyFuc... I mean FittyTucker.
Cheers!
To play Act II you need to reach the correct ending on Act I (You need to speak with Sloth) He will tell you to create a Special savegame, Act II will then recognize that save game when you press start. (The name of the save will be the one you gave it on Act I)
PS: If you are using android you need to allow the App to save files on your device.
Cheers!