I've played three of the Bridge Constructor games, and find this one to be the hardest, but not sure if it was the bridges or the insane physics. This was the most frustrating of the three, mainly because a bridge may be successful one time in 10, but for different reasons - jumped funny, strange ramp effects, or tumbling incomprehensibly.
There are two parts, the main continent and the unlockable slope world. The slope world is the twist on this version of the game that salvaged the review, as the main continent was simply three bridge designs in different lengths, depending on what supplies you were granted. Slope you have to think about it, and deal with the crazy physics.
Bought in a bundle for about 75c US. Played for about 18 hours, with 4 of that on just a couple of bridges (see my guide on the worst one IMHO). NOT worth full retail of US$10, but if you can get it for 2.50 or less I think you will find it to be a pretty decent game.
5.5 / 10