I also build some Pontifex bridges. First try: No matter how, the train just has to pass. Top wrecked bridge: >300 broken links (I made a bridge that, upon resetting, spawns 10 meter above the riverbed, falls into the water, pounds into the ground and only then is stabilized by ropes, worked remarkebly well). Second try: No broken links. Third try: As cheap as possible with no broken links. I completed level 10 and still had 24000$ left over.
I think I'm going to try those other games later.
Vain