The story goes; 

A sinkhole opens up in a remote location. NATO forces investigate and for protection they fence off the area. Then the Cartel of the area blows up the base. The player takes on the role as the last NATO solider alive. Your mission is to investigate, and go into the hole. 

What is in the hole? Nothing, or an entrance into some hellish place? 

This consists of 11 levels, 2 of which are secret. Various guns, lots of monsters.  There are bugs, big red ones. Updates coming when possible. 

*Level selection updated - should work now. If not - oh well. Hi ho. Diddle de dee. Why are there 2 buttons for 'Secret 2'? Idk, that's one of life's great mysteries. I'm sure I'll figure it out one day. 
*Some small fixes complete. 

** Mac & Linux versions untested.

Enjoy.