The commercial game, , is not free . It is currently available for purchase on Steam for approximately $20 .
Features buggy combat, useless iron sights, and a "psychotic" protagonist who rants about family issues while clearing tunnels. Tunnel Rats Free Download
There is a well-known free alternative called created by Xisumavoid. This is a Bed Wars-style map set entirely underground. Cost: Free to download for Minecraft Java Edition. The commercial game, , is not free