Hottaaman no Chitei Tanken [Model USE-HC]

Hottaaman no Chitei Tanken © 1986 Use, Ltd.

Players get to dig up dirt beneath the surface, find keys behind four doors, and then find the door to the next level. The most obvious game to compare it to is Dig Dug, but without the boulders and with various devices like teleporting doors, speed, dynamite, and a wet suit. There are 15 levels in the entire game; which repeat themselves after the 15th level is finished.

Items:
Z: It's okay to enter the lava for a while.
R: Increases attack range.
S: Blocks roads, making enemies impassable.
F: Enemies will come closer to the location you used.
N: Enemies will not come closer when used.
D: Destroy the block.