DO. NOT. BUY. - I hear some of the problems mentioned below are fixed in the sequel so if you want to spend money, spend it on that one, not this. Unless the devs come back to fix some major issues, it might as well be considered a SCAM at this point.
Update: since writing this review, the problems got worse. For whatever reason, information online seems to not be available for this absolute nonsense... But on 6-12, "transferrence" the game seems to actually be busted. You clearly need to use split joints, but the split joints are the wrong type and so you can't re-attach them on the other side.
I've looked up solutions, they all include the split joints working. When i look up why my split joints won't work, the best i found was someone saying "just keep reloading until they work" as if that's a solution, and after two hours of re-loading, it lterally has not worked a single time.
The game is absolutely busted.
I've almost completed it, having ripped my hair out in places because of the absolutely enfuriating nonsense that some of this game is.
It has puzzles that make no sense for the sort of game it is, which, okay, you need content. that makes sense. But then alot of the times the solutions make absolutely no sense, which, okay, again, guess can be excused- but then there's where the egregious problem comes in. the physics are HORRIBLE. It's a physics puzzle game, but literally you can have a bridge layout work once time.
Let me make this clear. There are times where you can change. ABSOLUTELY. NOTHING. and the bridge will work once, but not again. You might think "well then you got lucky" but then you can save and load that exact same bridge and it will WORK AGAIN.
There are points where i've had my bridges explode when all i did was move one piece, so i hit undo, it reversed it and the bridge went from working completely fine, less than 80% stress, functioning through repeated uses, to once again just EXPLODING.
It is enfuriating. If it were just 'x thing won't work' then okay. but you can literally have a functional answer to the puzzle, and it will just up and stop working, and worse yet, when you save and load that exact same answer, it magically works again.
At this point, nearly half the bridges i've had to put together for this require saving and re-loading them to make them function more than a few times in a row, because that's how inconsistent it ends up being. It's nearly consistent in being purely inconsistent with whether or not your bridge will just break and require you to re-load the thing just to make it functional again.