I've decided to try and incorporate many of the failed themes as possible into my build, as I suspect others might as well.
Conveyance
Not sure how to deal with this one, maybe some sort of moving lava or similar.
Based on children's toy (or part of)
This one is easy. My plan is to have a platform up about 6" above the tile that is the temple, with the space below filled with idols from other gods that have been thrown down into the pit below. I have some pieces already, including a beautiful Spinal Tap-sized stone henge that I can use parts of
2' x 2 ' game board
As this is designed to be part of a larger board, got this one covered
nature's bounty
Part of the commercial pieces I plan on using include the sponge-y growth things you see in my existing pieces
stealth
The upright for the platform (either a wall, a tower or an upright stone - unsure yet) will have a secret passageway built into it to allow the bad guys to move from the floor to the platform