first introduction - playful or aggressive?

Today I let the new kitten (Male, 9 weeks) and my female 2 and a half year old cat meet. We had them separated for the first few days (i realize it probably should have been longer). Anyway, the kitten was running around checking things out and playing all over the place, and when chanel came up to him he raised a paw as if he was going to swat -- throughout the meeting they were raising paws at each other, occasional swings (without contact)and occasionally doing those butt wiggles and pounces at each other (mostly the older one was doing this), but never fully making contact with swings or pounces. There were absolutely no hissses, but I am concerned -- is this playful behaviour? Or aggressive behaviour and should I intervene if it happens again? I only let them together for about 20 minutes today and then separated them again.

I think it was somewhat defensive yes, but as no hisses or growls - certainly not aggressive.

It is going very well! Proceed to have an eye on them yes, but dont worry and be optimistic.

This meeting was well above average - you may be pleased with your two kind cats.

Let them be together longer time! They will be pals very quick if you let them.