can someone help? Pleeease

what's the crapiest, lightest playable multiplayer shoting game that even a windows 2000 can handle?

I need to set a score with a rival (also a friend) to prove who's the best player...

atari 2600 emulator. play combat or outlaw

Yes, yolomate is right, MAME have so many multiplayer shooting games and Windows 2000 can handle MAME without major problem.  

I recommend this MAME one -- Change Air Blade -- basically a fighting game in a shooting game style  :



Straight from hardcoregaming101.net:
"...........Out of the many, many different kinds of shoot-em-ups, however, one has always been neglected: the competitive shoot-em-up. Most shoot-em-ups offer a two player mode where you and another player work together to clear the game. On the other hand, how many do you see about going against another player?

When you actually start a match, it looks like a cross between your average shoot-em-up and a fighting game. One player stays on the bottom half of the screen, the other hangs at the top, facing towards the player on the bottom. Your objective, basically, is to shoot down your opponent before he can do the same to you. It's a three button setup, with the shoot, bomb, and option buttons........."