Full list of all 50 Deadpool achievements worth 1,000 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox 360.
Completed the game on Ultra-Violence! difficulty
Completed five Gold Challenges
Scored a combo of 75 or more while fighting up the stairs at the "Front Gates of EEEEEEEVIL!"
Completed "Front Gates of EEEEEEEVIL!" from start to finish without dying
Completed "Front Gates of EEEEEEEVIL!" from start to finish using only swords and pistols
Completed "Landed in Prison" without countering any attacks
Got through Toxic River without falling into or touching the water and taking damage
Used all three switches, defeated the two phasers, and chased after Vertigo within 60 seconds
Combo-ed an entire wave on any Gold-tier Challenge map
Upgraded all weapons to max
Died 10 times in a row through the floating stairs
Made it across the floating debris without falling
Completed a Gold- or Silver-tier Challenge while countering at least 25 times
Shot everything from the Wheel of Insanity (Balloons and the Cow)
Killed 4 enemies in the Tower Plaza with stealth kills
In "Genosha," reached the fan girl using only Hammers and Pulse Rifles
Got from the studio lobby to the boardroom without dying in 5 minutes
Killed a total of 15 enemies by holding cooked grenades
Took no damage on the waterslide
Defeated Arclight while taking no damage from her slam attacks
Banked a 300-hit combo
Got off your well-toned bottom
Made a thousand pancakes
Was pretty
Played with Deadpool's junk
Completed "Job One"
Completed "Taking A Chance"
Slapped Wolverine a bunch of times
Played WTF is Cable
Completed "Genosha"
Interacted with all the ladies at the Shower Surprise Party room.
Heh heh, good times
Got a stealth kill with every melee weapon in Sinister’s Lair without being detected
Stealth Killed Sinister, in the Prison, with the Sword!
Completed "Landed in Prison"
Got a high score at the Carnival
Found 11 treasure chests in the darkness of the Tombs
Chose the patience option all the way through the line in the Carnival
Collected 100 tacos
Beat "Death, Baby" while wearing the pirate hat
Completed "Death, Baby"
Collected all DP points and ammo in the bathroom
Shot up the copier in the bridge offices
Completed the Breach in 10 seconds
Completed "The Road to Victory"
Completed "Front Gates of EEEEEEEVIL!"
Completed the game on Veteran difficulty
Purchased all Player Upgrades
Scored a combo higher than 40 before they locked the elevators
Set the Dialog Volume slider to zero