I had a go at building a more substantial bridge and found it hard to get right.
One nice thing about it is that if part of the structure is weak, the parts under the most stress begin to glow, and get highlighted.
Parts of the structure creak and collapse at times, turning a darker colour, which was confusing at first as although the structure had 'collapsed' it actually stayed in place, that is it cracked away from the original structure but didn't completely fall away, so it wasn't obvious it had collapsed and I could no longer join things to it. It highlights these bits with a red outline instead of a green outline.
It's important to know the controls, using TAB key to go into first person mode is much better. The game was pretty laggy at times.