Looks nice. If you haven't sealed it, you might want too... They pee on wood like crazy and it is hard to remove. I had to get rid of my wooden houses because of it. Interesting design though, I'm sure they enjoy using it. You might also be able to keep some of the pee off it by putting a layer of something absorptive (like a uhaul pad) with fleece over it on the bottom of the tunnel.. That would help a lot at least.
That's really awesome! I've been meaning to try and add creative things to the cage but just haven't had time. Can't wait for my little Thanksgiving break cause I'm going to go crazy decorating lol. But that looks very nice and they look like they love it!