Just got around to playing this one Pammy - I'm so far behind
The model is wonderful - very clever to set it sunken in the water so the generator and boxes are submerged a bit.
I got a really mystical effect when building a bridge in the direction of the cannon - there was a sound as if each box had been blown up, then each box disappeared (but the invisible bridge was still there!

) I don't know how you did that!
Keep up the model making, you're doing great.