I wouldn't say it's good... You probably got hit in an area where a lot of capillaries are close to the surface of your skin. Bruises are caused from bleeding below your skin. I wouldn't worry about it, unless it starts swelling badly, or the bruising spreads over a large area. If that happens, you might want to have it looked at by a doctor. That's not a very good idea for a game, you can get blood clots & those are definitely bad.