I've been testing it and got 5.5USD out of ~50k page impressions and 68 clicks.
And the revenue only went up if someone clicked. So I can say that for sure.
You ought to be doing a lot better than that. You need to have a bit of text on the game page (even if it's just in the description tags), and on pages linking to the game, so that Google can run appropriate ads. If your page starts to have a higher click-through ratio, advertisers will need to pay you more per click.
It's been a long time since I updated my web games, but I get about 13,000 ad impressions per day, and about 500 clicks per day (makes about $30/day). When I first released QWOP, it was getting about 2500 clicks per day.
The page has meta keywords, a description of the game, it even has that comments to avoid adsense getting the wrong info ("weight=ignore" something...). The ads where somewhat game related allright.
The setup was
AD GAME AD
AD
But, all ads were
text-only. Perhaps it has to do with that.
We can take this to another topic if you want (to stop polluting Adam's)