Here is the full list of all 21 Bridge Constructor Playground achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
25 failed simulations in a row for the same bridge.
Ran a level simulation although not one single element had been built.
Built a bridge with at least 100 construction elements.
Spent at least 100,000 for a bridge.
Achieved all badges for all bridges!
Cars can drive on all of Island 4's bridges.
Completed all levels with trucks.
Trucks can drive on all of Island 4's bSouths.
Cars can drive on all of Island 2's bridges.
Trucks can drive on all of Island 3's bridges.
Trucks can drive on all of Island 2's bridges.
Achieved 90 badges!
Bridge completed although at least 1 part broke.
Achieved 55 badges!
Cars can drive on all of Island 1's bridges.
Trucks can drive on all of Island 1's bridges.
Built a truck bridge which withstands over 95% strain without anything breaking.
Achieved 25 badges!
A vehicle flew at least 5 grid units into the air.
One vehicle reached the opposite side of the bridge safely, the other did not.