(bdubyah - just using your text as an intro. I don't disagree.)
How about TFP reduce game to 6 or 7 cube based shapes of 6 or 7 colors. (like a "T" or "l", etc.) that magically fall from the sky and you have to push them together to create congruous walls that block you from zombie waves? If you leave gaps it just makes it easier for Z's to get to you. If you match a certain # of colors, you get special aids that help (like oil to move blocks faster/easier). And every 7 days they fall faster. Oh, wait...
Smelter/forge/yadda: Roland used a word a couple years back that I have never forgotten: "abstraction". 7D2D, seems to me like a kind of post-apocalyptic simulator with lots of little puzzles to solve. Is it really difficult to imagine some kind of tool (forge/smelter) that's used to create things to make some thing to make moving or fighting or whatever better/easier? I'll grant you using a microwave to create a gyrocopter might be stretching it, but what they have in place seems imaginatively reasonable.
And, btw, TFP, while it's been a couple years, I just wanna say I am loving A20. RWG, districts (etc.) and new POI's are freaking incredible. (Not perfect - but wow.)