All weapons are Guns of some sort

There are 5 guns Geno can use.

Finger Shot:

Described in the equip screen as "Fingers shoot bullets." Geno will fire a lode of pellets at the enemy and it will make cause a splash of small stars when they hit. If you scored on a timed hit, a huge star shaped flash will occur before the splash of small stars. This is Geno's first weapon. After Geno joins you party, go back to Gaz, and he will give Geno the Finger Shot for free. The Finger Shot has an attack rating of 12 and can be purchased at the Moleville Item Shop for 50.

Hand Gun:

Described in the equip screen as "It packs a kick." geno will shoot a lode of bullets at the enemy and it will make a splash of small stars when it hits. If you hit a timed hit, there will be a big star shaped flash before the splash of small stars. This is Geno's second gun. The Hand Gun has an attack rating of 24 and can be purchased at the Marrymore Inn\shop, the Seaside Town Weapon and Armor Shop, the Sea Item Shop, and the Sunken Ship Salesman for 75 Coins.

Double Punch:

Described in the equip screen as "A handy double rocket Punch." Geno will launch two rockets at an enemy and it will make a splash of small stars when it hits. If you scored a timed hit, a big star shaped flash will occur before the splash of small stars. This is one of the easiest of his weapons to get a timed hit with. Geno's Double Punch has an attack rating of 35 and can be purchased at the Seaside town weapon and armor shop for 88 coins.

Hand Cannon:

Described in the equip screen an "Shoots bullets from elbow." Geno will fire a bunch of large bullets (little cannon shells) at an enemy and will conclude with a splash of small stars when it hits. If you hit a timed hit, there is a big star shaped flash will come about before the splasho of small stars. This is the best weapon that can be purchased in a store for Geno.Geno's Hand Cannon has an attack rating of 45 and can be purchased at the Nimbus Land Item Shop for 105 Coins.

Star Gun:

Described in the equip screen as "Try Shooting Stars!" geno will fire a bunch of stars at an enemy and it will make a splash of little stars when it hits. If you did a timed hit, there a big star shaped flash will occur before the splash of little stars. This is th strongest weapon that is in the game for Geno. The Star Gun packs a attack rating of 57 and can be found in Bowser's Keep after completing the Gu Goomba Fighting Room, that is in on of the 6 big red doors in there.