Thanks for sharing technomancy. I agree, in the past it was quite stressful to try all games in only 3 days. This time around one could really enjoy each game.
Perhaps in future jams we can communicate the expectation that one should rate all other games (or as many as possible) right at the start of the jam (perhaps even on the front page) and see if that makes a difference. Perhaps people are not aware they are expected to rate everyone else.
If that does not drive ratings up I could imagine stronger incentives : for example, one would only see ones rank but not the ratings across the 3 categories if one has not rated more than 1/3 (or 1/2) of other submissions. Thinking out loud here.
Certainly the fun of game programming outweighs this issue, I just wanted to bring it up as I had run a quick analysis of my past contributions and noticed the low ratio of rating to submissions.