His new toys arrived a couple of days ago. The first time I gave them to him, I wasn't in the playpen with him as it was cage cleanout day, so I was busy doing that. He seemed to love the toys, particularly the edible ones!
But then yesterday, I tried going in the playpen with him again, with the new toys as well, but he spent most of the time trying to scale the sides and escape! I don't know what I was doing to upset him - I've been in the playpen with him plenty of times before, and he's definitely not afraid of my hands as he'll run towards them looking for treats. I was sat really still and only moving my hands. I don't know - maybe it's the first time it's dawned on him that the big thing in the playpen is actually alive!