The game itself actually works quite well. The only part that stopped working ages ago was the glider craft coming out of the pyramid.

The Pyramid is held open by a coil very similar to a flipper coil A-31272 - high and low power windings so that it can be held in the up position without the coil burning out.

If that coil fails (and it did on mine, so perhaps not uncommon), the glider craft will not work.