The next game I'm playing is WOP (World Of Padman) and it is a shining example of what Open Source games can be!
This is one of those FPS games you find yourself asking: "Why in the world did they not make this commercial??"
The game oozes style and being a Quake 3 mod the GFX side of things are very well covered. It's even got an intro video! All the bells and whistles!
There are plenty of game types to keep you occupied and happy, from the free-for-all to all sorts of team based assignments.
The game play is again fast (not as fast as Nexuiz though) but the maps are HUGE so it is easy to run around not getting a kill cause you are in the wrong place at the wrong time.
The weapons are, I think, what makes this game fun!
From a psycho duck melee weapon to the sweetest sniper water blaster! There are only 2 weapons that I can quickly think of that uses conventional ammo, the rest are either water balloons, paint ball guns or some giant water pistol.
Have a look here for some screenshots of the weapons.
Have a browse through the site and take a look at some other screenshots on offer there, I took a couple but the homepage has far better looking screenshots!
I would rate this game very highly and I would venture to say that it will be a hit with all FPS players at any lan party, or to just get a quick frag against a couple of bots...
The game is available for Windows, Linux and Mac, so what are you waiting for??? Get it, try it and fall in love with it!
I leave you with one last comment:
The manual and intro video, enjoy!