From the App Store:
Mr. Dig loves collecting gems. One day he dug too deep. Monsters escaped from the underworld and stole his treasures and food! Help Mr. Dig and his friends battle his way through over 50 progressively tricky levels to get his stuff back.
To complete each level, collect treasures then return to surface. Make sure to leave an escape path! On monster-only levels, defeat all monsters then return to surface to clear.
Stuck? Support page and handy in-game "Contact Author" button can be used to request hints.
Look at the third image. The yellow squares indicate where Your Man can travel to.
I didn't get very far. I solved 7 or 8 levels. They actually get quite tricky.
The main drawback is the graphics. More modern graphics will draw in more users.