Cyberdogs
 

Hi, I remember playing a game at a... place where you waited after school for your parents to pick you up? Whatever. Anyway, I remember playing the game sometime between 1997 and 2000 (I remember playing on a machine that also played Jedi Knight, if that helps). The game was a top down shooter. You were one or two dudes in sunglasses exploring some kind of maze, collecting keys and such, and shooting other dudes in sunglasses. I remember co-op was on the same keyboard. The only other thing I remember is the game was called something like Bad Dogs or Mad Dogs. Thanks already for your help.

...and found it. The game was CyberDogs (this is what it looks like, if you were wondering)

Yeah, CyberDogs... I gave it a try once or twice. Check out Chaos Engine in case you haven't, I think CyberDogs is a clone of that game so you might like it as well.

If you like CyberDogs, you should also look C-Dogs. It was kind of a sequel to CyberDogs, but someone has remade it to run on modern platforms (there's even a port for Android).
And saying that Chaos Engine is similar to Cyber Dogs is the best recommendation someone could give me about that game.