Excellent! I have one too and love it. They're bigger than they look on photos I think
I would recommend putting something on the floor for it to stand on, as our hammy chewed the carpet in the corners of the playpen (all four of them!).
I don't think it would work with a roof on top - the sides curve up at the top so it doesn't have flat edges round the top.
Has Percy woken up yet lol?