Get the Napalm Gun
In the first level go strait to the boss don't shoot anything and hold L, R and up. Let go in the second level and you will have the strongest gun in the game, the Napalm Gun.
In the first level go strait to the boss don't shoot anything and hold L, R and up. Let go in the second level and you will have the strongest gun in the game, the Napalm Gun.