All you played was Onslaught? Hmm. Well a supernode is something you have to capture to connect the dots all the way to the enemy's power generator. While you do that you have to make sure your enemy doesn't do the same to you so you have to destroy the powernodes that they build. UT2K4 comes with many other different gamemodes. There's Deathmatch (where people run around and kill), Team Deathmatch (where teams of people run around and kill), Capture the Flag (where teams capture each others flag and kill), Assault (where people must do certain objectives to win the map and kill people), Double Domination (where teams must capture and hold 2 points and score a certain amount to win and kill people), Bombing Run (kind of like Rugby with guns), Last Man Standing (like Deathmatch but you start out with a certain number of lives and last man standing wins), Mutant (dumb mode, I won't even explain it), and Invasion (where you and bunch of people fight of an invasion of bots.) And then there is Onslaught which you played which is about controlling nodes to connect the dots between your base and the enemy's and then destroying their power generator.