I like the idea, but as others have said it's tough to enjoy it with the framerate issues plaguing it.

You've gotten some good suggestions on it already, but another thing you could try is having separate levels with increasingly large buildings to avoid having to simulate everything at once.

The idea is not a bad one, the implementation is so-so. I'll just highlight some points:

• The game should have been built for Windows (or another OS, but not for the Web)
• Creating so many dynamic objects is a very bad idea. It was possible, for example, to make objects dynamic only near the player, and the rest of the physics is disabled (although, honestly, I doubt that such a solution can help)
• You don't even have to destroy buildings, because by the time you get to them, they are already falling apart themselves
• A tractor capable of driving perpendicular to the tracks?

Good concept! My pc has trouble running it but I It was satisfying knocking the building down! Would love to play a more optimized version!