Ashley Hooper hit a padded bar of a climbing frame at Once Upon a Playtime in Bridgend, and collapsed in pain.
The 31-year-old was rushed to hospital for emergency surgery on his spine following the freak accident during the £4.95 session.
Partner Carly Fraser, 29, said: "While in the play frame he hit his head on one of the padded bars with such a force it compressed his spine leaving him paralysed from the neck down.
"His spinal cord is bruised and swollen and because he’s got a narrow spinal canal there wasn’t a lot of room to allow for swelling.
"The swelling is compressing on nerves which left him in severe pains through his upper body."
Medics operated on his damaged spinal cord - removing bones from his neck to relieve pressure and adding a metal rod to keep him straight.
Carly said: "He is on flat bed rest for 6 weeks and in time we are hoping and praying that Ashley will start to regain movement of his limbs.
"He’s already made amazing progress."
Staff said it "quickly became apparent" the injury was serious and the Welsh Ambulance Service was called.
Carly added: "The doctors are very happy and while they can’t guarantee anything they believe that he’s heading in the right direction.
"Recovery of this type of injury varies from person to person but Ashley is so positive and confident and is fighting every single day.
"All we can all do is hope and pray for the best possible outcome."
The play centre encourages adults to play with their little ones during the soft play sessions.
It states: "Why should you miss out on all the fun!! All of our equipment is designed and built with adults in mind, so join in with the dress up and try out the slides."
The staff at the play centre has raised over £500 to help the family as Ashley recovers.
A play centre spokeswoman said: "We as a staff have been completely devastated by these events, but that does not compare to what Ashley's family are going through - and we would like to show our support for them."