linuX-gamers.net pointed out Sqdef 1.1E, a strategic tower defense game for the GP2X Linux handheld console. If you want to play a similar game on your Linux desktop, Desktop Tower Defense is a browser-based game which the Multiplayer blog named as its game of the year:
Some people have agreed with me that Desktop Tower Defense is wonderful, intoxicating, and addictive in its gameplay. But many have been flummoxed because I did not pick as my GOTY a truly grand, big-budget game. Lots of people seem to think that year-end lists should be reserved for epics like Halo or Grand Theft Auto. But that’s not what “Game of the Year” means to me.
The triumph of Desktop Tower Defense—and the workplace productivity tragedy—is that anyone who is reading my words right now could start playing the game in less than a minute.
We usually refrain from mentioning browser games here, but the high praise DTD has garnered makes it worth a look I think.