Gary passed a game on to me called Questionaut. It's a free game on the BBC's KS2 Bitesize site, described as the following: "Journey through strange worlds and test your knowledge of English, Maths and Science on this magical mission to recover your friend’s hat." It looks like it's by the same creative folks behind Samorost.
The game design is striking, and just like Samorost, involves a lot of click-based exploration. It's educational, but once you get into the game, you discover it's more of a pretty packaging for quiz format education. Not ideal, but each of the stages are related to the subject matter you get quizzed on. I enjoyed it—the quizzes seemed 6th grade level or so.
A couple things to point out in terms of Flash production: they are really clever about mixing beautifully rendered raster art with simple vector characters that are easy to animate because of their design. The sound design adds a ton, but the game doesn't take long to load at all. So they've definitely optimized everything well.
You follow a simple narrative as you travel from stage to stage, so overall, I think they've done a nice job of wrapping a story around a quiz game. And the puzzles you solve to get to the quizzes are also very pleasurable (to interact with, and watch). Nicely done!