I didn't really appreciate the spoilers for some of the recent movies you guys were talking about so please keep those to an absolute minimum for future episodes if you could. I had to mute the Podcast a couple times and skip past some spots because of them.
Anyway,
Stargate: Although you guys are looking at an XCOM style game, might I suggest something along a different vein? You guys mentioned Minecraft. I don't suppose any of you played Mystcraft? It's an insanely good mod for Minecraft that allows you to create your own dimensions. There's a whole bunch of modifiers you can choose to make your own worlds and an extensive writing system. You can even make your own portals with the books you make. Or you can make a book that will have everything randomly chosen and see what you end up with. Also, the recent No Man's Sky looks to be up your guys' alley as well.
The View From Below: It's a very intriguing concept indeed but no real replay value I'm afraid as most linear games go besides maybe trying to speedrun it. Also, the fungus sounds... A little too similar to the Flood. Now admittedly, Halo was definitely focused on action, sci-fi, and multiplayer of course whereas you guys would like to go for a more subdued Metro style to it I'm sure. Nevertheless, the similarities between the fungus and the Flood kind of nag on my mind anyway.
Different Fantasy Universes: Sorry, I have to point out another awesome book series. "The Mirror of Her Dreams" and "A Man Rides Through." Basically, in that universe (standard European medieval in the base universe) people can make these mirrors which point to all these different worlds in different universes all depending on how they make the mirror.