Mr. Dig

Mr. Dig is a Korean puzzle arcade game released by Sun in 2000. It is a blatant knockoff of Namco’s Mr. Driller released just a year prior.

The overall gameplay is very similar to Mr. Driller. You play as Dig No. 1, Susemi, as you dig through the planet in either 500m or 1000m challenges, collecting air capsules along the way and avoiding being crushed.

There are some noticeable gameplay differences:

While normal air capsules provide +20 air, bigger air capsules are also available and they provide +40 air. This is handy as air depletes much faster than in Mr. Driller.
Bombs will clear out three columns of everything above them, including you if you get caught in the blast. They are activated by touching them.
Collecting letters to spell out EXTRA rewards you with a bonus life.
After losing all your lives, you have the option to continue as it sends you back to the last depth checkpoint you reached.