Challenge/ Restricted Builds

I was curious if anyone else does builds with self imposed restrictions or challenges?

As a personal challenge I’m currently rebuilding the Skylands trash tower on the Pokemon Center island with the restrictions that it needs to be of a similar shape and size and that I must incorporate the existing blocks somewhere into the build. I can freely paint any of the blocks and any block of a similar material counts for the ‘damaged’ blocks. I’m finding this way of building surprisingly challenging but enjoyable, I’m still not done yet so if anyone has rebuilt this it would be great if they could share some pictures if come up with several different ideas that looks good but am currently having trouble coming up with a design that fits in with the rest of my Skylands.