The pixel spray is one of the spraytypes available to players upon completion of a hero-specific achievement in quick or competitive play, the other being the cute spray. It is unlocked upon completion, with no need to spend credits in order to use it. The sprays themselves are lower-quality, pixelated versions of the playable heroes.
Ana Naptime: Interrupt an enemy ultimate with Ana's Sleep Dart.
Bastion Triple Threat: Kill 2 enemies in each of Bastion's configurations without dying.
Doomfist Air Strike: Get a killing blow with Doomfist's full-power Seismic Slam in Quick or Competitive Play.
D.Va Shot Down: Prevent 1500 damage with a single use of D.Va's Defense Matrix.
Genji Their Own Worst Enemy: Kill 2 enemies with a single use of Genji's Deflection.
Hanzo Simple Geometry: Get 2 killing blows with a single use of Hanzo's Scatter Arrow.
Junkrat Mine Like a Steel Trap: Knock an enemy into your Steel Trap using Junkrat's Concussion Mine.
Lúcio The Floor Is Lava: Get 3 killing blows while wallriding without dying.
McCree Whoa There!: Interrupt an enemy ultimate ability with McCree's Flashbang.
Mei Ice Blocked: Block 1200 damage with a single Ice Wall.
Mercy Group Health Plan: Restore 200 health for 5 players without dying.
Orisa Halt State: Pull enemies into 1000 damage with a single use of Orisa's Halt!.
Pharah Clearing the Area: Knock an enemy to their death using Pharah's Concussive Blast.
Reaper Waste Not, Want Not: Get 3 solo kills with a single clip of Reaper's shotguns.
Reinhardt I Am Your Shield: Block 8000 damage using Reinhardt's Barrier Field without dying.
Roadhog Giving You the Hook: Interrupt an enemy ultimate ability using Roadhog's Hook.
Soldier: 76 Rocket Man: Get 2 killing blows with a single use of Soldier: 76's Helix Rockets.
Sombra Hack the Planet: Hack 15 enemies without dying.
Symmetra The Car Wash: Hit an enemy with 6 beams simultaneously.
Torbjörn Armor Up!: Have one of Torbjörn's Armor Packs on 5 allies at the same time.
Tracer Total Recall: Recover 400 health using Tracer's Recall without dying.
Widowmaker Did That Sting?: Kill 4 enemies using Widowmaker's Venom Mine in a single game.
Winston Mine Sweeper: Destroy 10 turrets or traps using Winston's Tesla Cannon without dying.
Zarya Power Overwhelming: Keep Zarya's Particle Cannon above 70 power for 60 seconds.
Zenyatta Rapid Discord: Get 4 kills or assists with Zenyatta's Orb of Discord within 6 seconds.