Linux games for the bored

In class, sometimes I just can't make myself care. Either I know it, or the professor just drones on. Luckily, I have my trusty IBM T60 running Ubuntu 7.04. Many people I've talked to about Linux vs. Windows cite games as a reason for staying with Windows. While this is true, there are many great, free games out there for Linux. There are also some commercial games that run on both. Here are some that I've enjoyed in the past:

Commercial:

Savage: The Battle for Newerth – This game is more gfx intensive than any of the others, and is now being released for free. It is a realtime strategy shooter, where players assume the roles of both a commander, and the soldiers on the field.

Free/Opensource:

Nibbles – This comes with GNOME, and is 'finger-twitching good' to quote one of the skill levels, play with up to 3 other people on some very challenging courses.

Tremulous – Based on the Quake 3 engine, it is a game that pits alien versus humans. Humans have guns and armor, whereas the aliens have more natural attacks, and some can walk on the walks and sneak across the ceilings.

Planet Penguin Racer – Control Tux as you race down the icy slopes in many of the user created tracks. Either enter a cup, collecting herring in a given time, or go for big air.

This is a very short list, but these are the ones I play the most, and are a nice way to while away the time.