Button Mania

Difficulty setting: - - -

Clicks used:

Current score:

Solve speed:

How to play:
Click on one of the buttons in the playing field
to subtract 1 from that button's value,
as well as from the values of the 4 surrounding ones.
Objective:
Set all buttons to '0'.
Example (a click on the "2" in the middle):
0
123
2
-->
3
012
1
Things you should know:

Valid CSS!  Valid HTML 4.01 Transitional