Sniper

How to unlock: The Sniper is unlocked after beating the game for the first time.

The Sniper is the ultimate boss killer. A perfect reload and a fully charged Steady Aim, along with Spotter: SCAN, can one shot many bosses. Try to stand in a preferable position where you can charge Steady Aim for as long as possible.

In the ending cutscene, the sniper-specific text says: "..and so they left, the sound still ringing in deaf ears."

Tactics

 * Prioritize STEADY AIM over SNIPE.  Only use SNIPE while kiting enemies in-between STEADY AIMs. With practice, you can SNIPE, then jump and perfect reload just in time to SNIPE again when you land. With attack speed increases, you can fire in the air without needing to land.
 * Don't forget to use Spotter: SCAN, as the amount of bonus damage you get from the guarenteed critical strikes can save your life.
 * When reloading the gun, you want to stop the bar in the white area for a "perfect" reload. The white area is close to where the bar starts off, so if you practice your reloads you can eventually get to where you make a perfect reload almost immediately after every shot. It's a skill worth learning.
 * The best use item for the Sniper is anything that can attack enemies without requiring aim, such as Jar of Souls, Glowing Meteorite, or even the Disposable Missile Launcher (but NOT the Sawmerang). This is because Sniper's only true fault is an inability to fight effectively against large crowds in tight spaces, so having an item that can kill from a safe location the sniper can't shoot from is practically a necessity.
 * Due to the Sniper's high damage and low attack speed, on-kill items such as Gasoline and Will-o'-the-wisp are more effective than chance-on-hit items such as Rusty Knife and Ukelele. Drones are also more effective with the Sniper as they benefit from the Sniper's high base damage. Finally, Crowbar dramatically improves the effectiveness of STEADY SHOT against undamaged enemies, and is among the best items for the Sniper.
 * As long as there's a lot of running space, Sniper can handle crowds just as well as (if not better than) other characters. Simply run away from the crowd to create distance and hit them with a STEADY AIM charged as much as possible before enemies close in. A great tactic for this is to turn around sharply when you're ready to fire, and then perform a backflip with MILITARY TRAINING for added distance before you start charging.
 * STEADY AIM will pierce through the enemies but doing so will halve the damage for every enemy it hits. Perfect reloads affect this ability aswell, granting a great damage bonus for a fully charged, perfect reloaded STEADY AIM. Furthermore, If you crit an enemy with STEADY AIM, all piercing damage after that will be crits as well.  This synergizes with SPOTTER: SCAN, allowing you to critically hit all enemies.