To get the Silver egg go to the lake with the waterfall near where knuckels is/was go up against a blue theing untill it goues into the wall, turn around and in the water there will be a silver egg.
To get the black egg play as Amy,Big or Gamma. Go to where the prison cells are where Amy was and in the Second cell there is a black egg press the button, take the egg.
Long Hammer: Return to the Egg Carrier when it's in the water and beat your previous high score.
Laser Blaster: In the opposite room where you got the Jet Booster (only obtained when Egg Carrier has crashed in the water).
Note: This trick will work for all GameGear Minigames but if the game does not support multiplayer, they will not link to each other (In other words the gameplay will be seperate per screen).