Very creative and nicely done!!! I have a few ideas for Phase 2, and then Phase 3, but haven't thought of a bridge like yours. What did you run through the timbers? I'm thinking cable so it will last.
Made the first one in the 1980s for my kids.
My daughter ( lower left kid) wanted me to make another for grandkids a few years ago.
First one I used ground wire from house service wires.
For the new one it was steel cable from Lowes.
Landscape timbers stained for bridge cut around 31".