I haven't seen a ton of this but I've seen it more than a few times, specifically with games that involve tiny planets and a player avatar that runs around them (guilty as charged). Naturally with my game being an offender I feel it's quite a disadvantage if a judge, after playing many games in a row that involve similar mechanics, gets annoyed and it affects feedback but only for the unlucky tail end of his/her judging spree.

Obviously I can't see anyone else's ratings so I have no idea if that's actually happening. But we all came up with ideas around the same time, so the likelihood of straight-up copying or mimicking is low (it's possible with people blogging early though). Maybe instead of docking overly-used mechanics that lots of people felt inspired to do by the theme, just give positive feedback for games that managed to have unique mechanics.

Not a big thing, but I thought I'd mention it. I'm sure we all thought we were geniuses as we each independently invented the wheel.