Cluttered housing

I've got a bit carried away thinking of ideas to keep the rabbits entertained but I'm not sure whether I should leave their run as empty as possible so they have space to run around or is it ok to put obstacles and boxes and things in there too? Which is more important do you think? Space to run around or things to keep them entertained. I have another run attached to their normal run so I could always put their toys in one and keep the other clear

It depends on the rabbit and what they enjoy doing. Frosty loves to jump onto things and from one thing to another so I've added more things to enable him to do that. Other rabbits might like zooming about and that would mean they would prefer a more open feel