I had 7 game designs for this theme when I left out from the door and almost an hour later, returned with 2 reasonable.
1st design I dropped was “topple the domino enemies side scroller platformer.” – Needed pretty good physics which I wasn’t prepared to do. Wasn’t that interesting either.
2nd dropped design: “Spread anarchy / chaos” was just something that popped into my mind and I couldn’t invent any new ideas for that.
With 5 designs left, each one interesting, in my opinion, I did 1-5 grading of
– how interested I was in doing the game
– how well the game matches given theme
– how unique the design was.
– amounts of game design, code, art and level/moster/other content remained.

3rd game to drop was the Political card/turn based one. Figured it would be difficult to make a proper AI or to make a muptiplayer.
4th dropped game, a Megaman clone, was too much work and not enough innovation.

I was left with “Meatgrinder+cannon on wheels, shooting ground human meat and metal bits from scrapped tanks” and “Puzzle where the evil ruler must remain in rule by pitting the citizens against each other”. Looks like there are plenty of “absorb enemy, shoot him as ammo” -designs so I’m going with the puzzle design. One problem is that I estimate that the puzzle requires more work than the arcade driving/shooting. Guess it’s time to fire up VC#.