A great free game, Echoes is Asteroids on crack. Binaryzoo.com describes it best,
"Yeah, it's a bit like Asteroids
hyperactive, drug crazed brother displayed in blur-o-vision©
and viewed through psychedelic sunglasses in a cheap nightclub."
The controls do take a little getting used to (mouse & keyboard combination) but the game is a lot of fun.
These games are by no way my personal favorites . They were just picked randomly out of a list that I play from time to time and they are games that I know will run on a thumb drive. Enjoy.
Lemmings
Who doesn't like Lemmings? This is a great remake of the classic game that runs off a single executable file and is only 21MB in size. It also contains all the original levels for hours of fun.
Pacman Worlds
Guide Pacman around many themed worlds. Collect all the Hidden and protected Gems, to bring back balance in Pacman World, where the Ghosts have been too dominant. A fun addition to a thumbdrive. Only 14MB in size.
Flight of the Amazon Queen
A classic Point and Click adventure game. The year is 1949. You are Joe King, a struggling airline pilot in South America. Trouble starts when Joe decides to fly actress Faye Russel to a distant location where she is expected to start filming her latest movie. Thanks to a gigantic thunderstorm they soon find themselves stranded in the vast jungle of the Amazon where a sinister plot involving a German lederhosen company and an ancient tribe of Amazon women develops. The game is 36MB (yes a little larger) and when you click the installer program change the destination install to your thumbdrive and it will work.