Hyper-V Program Manager
I suspect that SpitWad Willy is actually a clone of another arcade game - but I cannot remember the name of the original game (if anyone reading this knows - please post in the comments). In this game you take the place of 'Willy' who has to shoot 'spitwads' at a number of ball like object bouncing around the screen. It sounds kind of whacky but is quite fun to play:
SpitWad Willy runs well enough under Virtual PC - however I did have to use a 'slow down' utility in order to get it to a playable speed. You can download SpitWad Willy from here: http://www.worldvillage.com/wv/gamezone/download/spitwad.zip
UPDATE: This game is a clone of the arcade game 'Pang' - where you use a harpoon rather than spitwads. Thanks Aaron!