Dig! Stronghold Version is the fourth edition of Dig!.
Each time you click a stone block another silverfish shall spawn.
Points
Stone Bricks : 20
Mossy Bricks : 35
Cracked Bricks : 45
Bookshelf : 40
Portal : 150
End Portal Frame : 180
Silverfish : Game over

Go here for the other 3 versions : http://www.planetminecraft.com/mod/dig---game-not-mod/

There is also a secret room in this version that has only a 1 in 100 chance to appear

Once you do click on a silverfish, it will take you to the high score screen.
f4 is for fullscreen.
Please report any bugs or issues here.

Have fun!