should have actually answered the actual question.
Multi level games are fun and a little out of the norm(which is part of the fun.)There's two main draw backs/ pit falls.
Detail verse access. (Or sausage fingers and broken bits.) .
And the most common killer of multi layer and multi side boards is C.B.A.. Most gamer's are put off multi layer games as you keep having to get out of your seat to move things on the other side of the vertical support.
The best solution is to use a cake base with a swivel, underneath the board/terrain.That way everyone stays comfortable throught.Plus its quite useful as a suspense element.(GM turns the board round adds the nasty stuff you've just walked into then turns it back to face you.Much more interesting in a game than having individual items place one after the other in your line of sight.)
As for a pyramid it works two(GW did a multi level pyramid themed board game "Curse of the Mummies Tomb" .Infact multi layering is a staple component of children's toys.The dolls house is a multi layer toy .Theres plenty of board games done on multiple layers(even Star Trek had a multiple layered game.)
In short its very much a doable concept .What makes or breaks them is all round table access.
If you wanted to push the boat out you could bulid a board very similar to your rocket pics. Having the whole gaming area rotate with in the cutaway rocket model.
