What is JJ2+?
The JJ2 Plus add-on adds countless of features and bug fixes to the game.
It adds a scripting language that benefits level designers.
It expends the multiplayer side of things, like adding a lot of new game modes
(Roast Tag, (Extended/Team) Last Rabbit Standing, Pestilence, Team Battle, Death CTF, Jailbreak, Flag Run, Domination, and Head Hunters) and applying numerous bug fixes and feature additions to the old ones.
It allows you to use in-game commands for enabling or disabling game modes, weapons, and numerous other options like spectators or mouse aim gameplay.