There's this very old post on iPhoneDevSDK site in 2009 which "kwigbo" announced about publishing full source code for his "ABC123" cocos2d game. Unfortunately that link no long works and I wasn't able to find any source code on his site either.
Based on the same idea, I am currently working on "my implementation" of a game similar to "ABC123". I haven't learn COCOS2D yet, so all in basic iPhone code.
Already finished the logic, display and other stuffs. Only got a few things left like showing/keeping the score, showing how many "tries", ...etc. Hopefully can get it completed within the next few days.
Will keep you posted.