Absolutely great work!, I really like the game developed by you. Still playing and studying it.
A piece of advice for its betterment. In any new game the 9th row is always blank, It initially gave me impression whether there was a bug in the code, but later I enjoyed playing and debugging it. I hope some enthusiasts will suggest upgrades to it in due course of time.
Anyways thanks a lot for a gr8 code for a wonderful game :)
Effective solutions are worth stealing.
The only thing to do with good advice is to pass it on. It is never of any use to oneself.