Netbooks are small and best for mobile gaming as well but it depends on the type of games you like playing. Intel AppUp(SM) Center has some great games and I would suggest it for all. But today I will be listing 5 open source games that are available and they work just great. The most important feature of the games are that, they are FREE!!
In this game you have to tilt the floor to roll a ball through an obstacle course before time runs out. Neverball is part puzzle game, part action game, and entirely a test of skill.
Aleph One 0.23.2
Aleph One is a free software first-person shooter game engine based on the source code of Bungie Software’s 1995 game Marathon 2: Durandal.
The Battle for Wesnoth is a turn-based tactical strategy game with a high fantasy theme.
OpenCity is a full 3D city simulator game project
Dink Smallwood V1.08
Dink Smallwood is a humorous zelda-like isometric adventure/RPG produced and published by Robinson Technologies in 1997
Crossfire is an open source, cooperative multiplayer graphical RPG and adventure game.
These are list of only few of the many available free open source games. More are available at Netbook Games but I will post another update soon with new list of games to play. As always, leave comments and I will try to respond to them as soon as I can.