We have 3 seperate varieties of this at our state fair:

One looks like a flying saucer you get inside. Pretty much no rules, and you always have some brave soul that stands on the backrest with their head toward the center so that they are horizontal with the ground.

Another tilts up at like a 45° angle part way through the ride and you can only stand against your backrest. If the ride fails, there's a flimsy little waist-high chain to "hold" you in.

The last one looks like what is portrayed in this picture with one continuous carpeted wall. The floor drops down while you are stuck to the wall, and you can get horizontal like the girl in the picture. Eventually they slow the ride and you slowly slide down the wall to the lowered floor.