Little Keep on the Borderlands (2002)

From the back of the book:

As you will soon learn, the plight of mankind in Garweeze Wurld is indeed great. And although there are those who deny the obvious, man's future here looks bleak. On all sides, the forces of evil and chaos press upon its borders seeking to bring mankind to its knees, intent on enslaving its populace, raping its riches and claiming mankind's lands as its own.

Cast in the middle of this chaos, like an island in the midst of a tempest-tossed sea, stands the little Keep on the Borderlands. Its small garrison is the only thing keeping evil from pouring through the pass of Hell's Throat and into the realms of humanity. It is a battle they have fought well, but one they are slowly losing. New heroes are needed to bolster their ranks. Do you have the mettle within to become great and answer the call?