When I looked at Carwings' numbers, it was clear that some of those were simply unrealistic. This suggests there are ways to "game the system". I think it may do some of the ratings based on "a trip". So if you turn the car on, coast down a long hill, and turn the car off at the bottom, you just scored an incredible rating on that trip. That's a guess, but I suspect I'm not far off.
As for regenerative braking, in the real world, regen is regen. The drag you get when you take your foot off the pedal is the same thing you'd get if you didn't have that and instead, lightly applied the brakes. Either way, it slows the car down, and it does so by generating juice back into the battery. Regen is better than friction brakes, but it's not as good as not needing help to slow down in the first place. You can do that by not going too fast in the first place. Of course, on hills, you probably don't have a choice, unless you can avoid having to go up the hill in the first place.
Unfortunately, some of the games like the rankings, and the "trees", seem to encourage using regen. This could result in some non-ideal driving habits. But, hey, having a LEAF is just so much cooler than anything else, who cares how you drive it?