At the halfway point in the 3rd level, where the ship alternates between dropping grenades and soldiers, stand all the way to the left and aim your gun to the right. Fire to the right and leave the game running. If you leave and come back atleast a half hour later, you should have 30 lives on the counter.
To get the best gun, make sure the difficulty is on normal or hard. Play until you get to the sixth stage. When you get to the final boss, it will have different shapes going around it. Try to shoot the one that looks like a spike. It will drop lots of guns and bombs. Get under the boss and wait until the gun "M" pops out. It is the strongest gun in the game
