OpenLieroX is based on and compatible to the famous LieroX. LieroX is a 2D shooter game. It is an unofficial sequel to Liero, and is the most popular of all the Liero clones. It features online play, fully customizable weapons, levels and characters. Liero Xtreme was created in C++ by Jason 'JasonB' Boettcher, an Australian programmer.
The game is based on a deathmatch setting, where multiple players face off in a closed level, however single player with AI is possible. Each player is equipped with five weapons selected out of all the weapons allowed, and with a ninja rope that allows the player to move in any direction. Players begin with a set amount of lives, and whilst the game records the number of kills, the last man standing is usually considered the winner. LieroX also allows team deathmatches, which has made it common for players to form clans.
There are many mods available for the game.
It became open source in 2006 and the source quality has increased much since then. The size of the overall source has also doubled in size. Most features were developed in a way such that they can be reused in other projects, so the source can also be very helpful for other open source projects.