12 Hour Layover in Rio Airport - What To Do?

Similar to Vizbiz's request about LAX....
#1 Son has managed to land himself with a 12 hour wait in Rio at the end of his round the world trip at the end of August. I can see there is at least one paid lounge, but it has a 3 hour time limit.
Has anyone out there experience of the airport and what he could do to while away the 12 hrs?
Thx
Paul
#1 Son has managed to land himself with a 12 hour wait in Rio at the end of his round the world trip at the end of August. I can see there is at least one paid lounge, but it has a 3 hour time limit.
Has anyone out there experience of the airport and what he could do to while away the 12 hrs?
Thx
Paul