The outside rim of the satellite is constantly pushing at the object to keep it in its circular path. If you took the wall away, the object would just keep on in a straight line. The sensation of the outside rim pushing on you (the object) is precisely the same as the sensation of the ground pushing up at you when you are standing on Earth.
Acceleration towards the centre of rotation is indistinguishable from a gravitational force as long as
1. The object is small compared with the radius of the spinning ship and,
2. you don't try to move about. If you go to touch your toes, you could fall over because of an effect knows as Coriolis Force.