Complete the following tasks to obtain the corresponding weapon.
Talk to king when you have defeated frenzied Toroko. He will ask that you avenge him and then disappear. When something takes his place press 'Down' to get the weapon.
Get access to the Bushlands and obtain jellyfish juice. When you have it go to the meeting room in the Mimiga Village and put out the fire.
Obtained in the Bushlands when you talk to Santa after getting his key.
Unlock Machine Gun:
In the Sand Zone defeat Curly and she will want to trade the Polar Star for the Machine Gun. To get the Spur later you must refuse her trade.
Unlock Missile Launcher:
Found in the treasure chest in the Egg Observation room in Egg Corridor (the second door with the save symbol).
Unlock Missile Upgrade:
When you defeat Balrog in the Boulder Chamber a treasure chest with the weapon will appear. If you already have the Missile Launcher it will be upgraded to fire new missiles.
Dragon and Kazuma will be on the Balcony so you need to go down a row to find a gap and use the Booster to traverse the gap and enter the house. Talk to Mrs. Little then go to the Graveyard. Speak to the small character in the grass and he will enter into your inventory. Return to Mrs. Little's house. The small character will say 'I'm home!'. Talk to him in the house and he will trade the Blade for the Nemesis.
Unlock Polar Star:
Obtained at the start from the hermit gunsmith.
Talk to the owner in the Labyrinth Shop and he will borrow your Polar Star and Fireball and combine them into the Snake. This weapon's rounds will pass through walls only if you do not have the Machine Gun or Spur.
Defeat the fish Boss. After appearing in the Reservoir, go to Arthur's house. Professor booster will appear from the teleporter and give you Booster 2.0. Before this you must not talk to Booster in the Labyrinth. Use the Booster to reach to the first cave and talk to the hermit gunsmith and he will upgrade it to the Spur.
Added by: Sanzano Apr 19th 2012, ID#339