The Shock Blaster is given to Ratchet for free on Veldin. It can be upgraded to the Shock Cannon with use. Upon reaching challenge mode, it can be upgraded to the Mega Shock Blaster for 420,000 bolts.
The Shock Blaster was referenced by name in a Courtney Gears album titled Oops, I Got Vaporized By A Level 7 Shock Blaster!.
The Shock Blaster is a short dark blue shotgun with silver highlights, a glowing scope and a left-hand grip. The Shock Cannon is longer, with a much wider nozzle, and more metallic highlights. It fires a wide blast of energy at targets.
The Shock Blaster deals damage in a wide radius in front of Ratchet, dealing decent damage. It is therefore most useful against large mobs of small enemies. Against larger enemies, it is less effective unless charged up (which is possible at V2). As it is an early weapon, the Shock Blaster becomes outclassed later on by much more powerful weapons which are more versatile, such as the Plasma Coil and the Annihilator.
The Shock Blaster improves with upgrades. At V2, it is possible to charge the weapon up by holding down the fire button, releasing a more focused blast dealing greater damage, which makes it far more useful against larger enemies. At V3, it can lock onto enemies. At V4, it can affect enemies close to those hit with electricity, improving its use against large mobs of enemies. At V5, as the Shock Cannon, it is far more deadly, and can be charged up for an even greater and more focused blast.
Notes and references