As Julie said, it is very common to have cats acting completely differently, especially if they have gone from a multicat household to a non cat/smaller cat household. I spend a hour with foster cats (excluding feeding/cleaning), and it depends on the cat what we do - some prefer to just sit on my knee, others prefer to play - Ellie seems to vary, some days all she wants to do is play, others she wont entertain Da Mouse, and I have to sit and fuss her instead. I do play with interactive toys, as she doesn't leave the cat room, and is only a youngster, so she needs something to help with her energy. I have never really had a problem with cats going to new houses and not having as much play time as here, although I know it has happened, although more often than not they are indoor only here and allowed out in their new home, as well as not being confined, so dynamics are different when rehoming anyway.