Free Hero Mesh level file
From Just Solve the File Format Problem
A Free Hero Mesh puzzle set consists of four files; this article is about the .level file, which contains the levels.
This file is a Hamster archive which contains lumps with extension .LVL, where each one is one level. The CLASS.DEF lump associates class names and message names with numbers; those numbers are then used in the .LVL lumps.