Everywhere near the very beginning of the game, near the yellow tuck and near the verification table, has very iffy physics. You get stuck a lot and have to jump around. At the "Construction Halted!" Screen, the mouse is invisible and doesn't seem to be moving around. My debugging skills tell me it's because it is still making the player look around in the game rather than making the mouse move on the screen. I also recommend allowing the player to navigate the menu with the arrow keys or WASD. Or even just ESC/Enter since it's a simple yes or no menu.