An Advantageous Way of Re-arranging the Game Grids

     Creating Stone Henge type structures or mazes confuses the robots.  When you hide inside one of these, the robots have a very hard time finding their way in.  You can then blast them through a hole before they find you.
     The more exits you have from the place the better.  If a robot finds its way in, you probably won't have time to turn and shoot it before it blows you away.
     Mazes can screw you up, too.  If the walls are too close together, you will have a very hard time moving around.

Limits on the Number of Obstacles

     Spectre does not allow more than 55 obstacles on a game grid.  I have assurances from the authors that this limit will never change.  I believe that it stems from the finite speed at which Spectre can calculate and update the screen.  If you’re wondering how serious “never” is, consider the fact that they hard-coded the limit!
     If you place 55 obstacles on a game grid, Spectre won't give you any ammo dumps when it uses the game grid!  On level 1, that's not a problem, but if you want to do that on level 30, you won’t survive.

How Spectre uses the Game Grids

     Each of the 9 game grids (0-8) is used for a few consecutive levels and is probably never used again.  For example, game grid 0 is used for levels 1 and 2.  Then Game grid 1 is used for a while.  And so on...