I've played with a flash game years ago which I really enjoyed and no matter how hard I try I can't find it.
What I remember:
- you controlled more than one characters (4 if I remember correctly)
- not all of the characters were humans (there was at least one which was a cat or a dog, I don't remember)
- you were able to change the control between your characters and you had to work with all of them together to win the map (aka Lost Vikings)
- its arrangement was like dyna blaster or zelda so you've got a screen with a task and you had to use all your characters to solve it
- its music was really catchy, it's till in my head after years and if I know well the brass instruments the solo was played on a trombone (or a tuba)