my baby sleeps in the bassinet that came with his pack n play. I figured when he can sit up and crawl around I'd put him in the 1st or second level to play.

Mine zippers in place.

Yes. My baby slept in it for a little. Safe until they start rolling over, I'd say.

Mine is where you can place a mattress ( fit the size of a mini crib)

yes, that's the bassinet function