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 charge 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.

Tactics

 * For the most part you want to spam STEADY AIM and ignore SNIPE altogether. Only use SNIPE if you just want to finish off an enemy already near-dead or when STEADY AIM is in cooldown.
 * Don't forget to use that spotter, the amount of bonus damage you get from those gauranteed crits 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.
 * 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.