The second camera I had was one of these. It was another fixed lens (focus, aperture, and exposure), but using Instamatic cartridge films. The quality of them wasn't too good, though better cameras did take quite reasonable pictures with them. Their ease of loading was their best feature, you just dropped the cartridge into place, no threading, and no careful fitting into place was needed. I think you could even get away with taking a partially used cartridge out of the camera, though you'd lose the frame it was currently wound to.
The only special feature this camera has was being able to plug a flash cube into the top. I never did work out how it blew the flash, there's no power in the camera, and I couldn't see anything in the cubes.