Originally Posted by Taeles
The iap comes in two forms. 'Hints' for bridges troubling you and a cap removal on how many bridge pieces you can place on a map. The hints you can easily google for free, and the game gives you ten iap currency out the door and you can easily use that on one of the final maps to knock out the value and object count achievements.
Zero iap required.
Until you get stuck. I have its predecessor, Bride Constructor Playground and it won't let me go on to the next set of levels until I had enough stars. Stars are earned by accomplishing all the goals per level. So yeah, no need for IAP if you just want to play the first few levels only.