My entry:
http://ludumdare.com/compo/ludum-dare-3 ... &uid=36700
And here's what it looks like:
Yes, the unconventional weapon is merely some attractor, that you must use to deflect the enemy shots back toward them. I know, it's lame and unoriginal, there must be hundred of submissions based on the same idea.
So, as the compo ended, I switched to a new mechanic, where the unusual weapon are instead the enemies themselves! I know, it's even less original, I already saw other submissions with that gimmick, and I haven't yet started looking. So you catch enemies with chopsticks (I hope this count as unconventional weapon?) and then, presumably by stirring their entrails with said chopsticks, you force them to use their special ability at your will.
As you can see, the goal is the same, it's just more convoluted.