+=3

This is a troll game in multiple ways. First of all, there is a troll. The point of the game is to cross the bridge that he is guarding.

Second, it's designed to have a ton of red herrings, like an overly-complicated calculator and a recurring noise.

Third, the whole point of the game is to prove a point in an argument.

The main argument is whether a logical solution is a solvable solution (and the point here is that the answer is 'no').

This remains a big sticking point in parser design three decades later. Many authors are surprised to find players getting stuck in parts of the game that should be logically clear or blindingly obvious; a lot of this is because for most parser games there are many logical things that we politely ignore, like realistic carrying capacities or getting tired or using the restroom. Those things are ignored because, when implemented, they are generally dull and boring. The experience of playing is, to me, more important than realism, and that ties back into this game's themes; while the game is logical, it not an enjoyable experience.