Not so informative, but mildly interesting – Kanji Game 漢字ゲーム Review

It's an interesting idea. It will train you to get a sense for the patterns that exist in kanji (which you would would naturally develop anyway by studying kanji)... but it won't actually teach you the kanji readings or meanings, so as an educational tool it's a bit useless. You can use it to test your "feel" for kanji, I suppose.
Review by QuantumAnomaly on Kanji Game 漢字ゲーム.