Wasn't sure which one to put this under but I figure I'd mention some achievements which seem to be a bit grammatically incorrect. I know it's being a bit picky but if nothing else, if you want to correct it, these are probably the best ways to do so and if not, well, nothing lost really.
Anything that reads "...without been..." which would read better as "without being..."
Examples include: "...win one round without being knocked out", "...win one round without being frozen", " for 45 seconds without being blown by the wind" etc.
Anything that reads "(require more than" which would read better as "(require_s_ more than"
Case Closed: I think it would read better if it was changed from "by throwing it into the hatch" to "by throwing them into the hatch"
Still Waters: I think it would read better if you added "comes" to the end of it
For example: "before the 3rd wave" to "before the 3rd wave comes"
Man vs. Wild: It's technically fine as is but I think it would read better if you changed "get back to one bonfire" to "get back to a bonfire"
Perfect Guard: This one needs a bit more help. It would read best if you changed it to "parry the hockey puck with a shield for 3 times" so it comes out "parry the hockey puck with a shield 3 times"
Tarzan: This one also needs more help. It would read best if you changed it to "survive 20 seconds after the main rope break_s_ up and win the round" so it comes out "survive 20 seconds after the main rope breaks and win the round"
10 Quick Match Wins: I would just do this: "Win 10 Quick M_atches in the Quick Match" so it looks like "Win 10 Quick Matches"
Dutch's Plan: It would read a bit better if you changed it to "experience a team wiped out" so it looks like "experience a team wipe out"
Who Did That?: Just a simple addition: "Throw an item"
Immortal Kombat: Two small changes: from "knock out opponent playing arcade 3 times in one game" to "knock out an opponent playing an arcade machine 3 times in one game"
First Strike: Similar to 10 Quick Match Wins: "Win 1 _Quick M_atch in the Quick Match" so it looks like "Win 1 Quick Match"
Ball Weapon: I would re-word most of this depending on what the objective is:
(Throw the ball and have it knock out the opponent) "throw a long pass that knock_s_ out an opponent" so it reads "throw a long pass that knocks out an opponent"
(Throw the ball and then knock out any opponent regardless of whether you did so with the ball) "throw a long pass and knock out an opponent" so it reads "throw a long pass and knock out an opponent"
Sayonara: Like Case Closed, just by changing "hitting it off the field" to "hitting them off the field"
The Vortiguants: Just a small change of "survive from the 4th black hole" so it reads as "survive the 4th black hole"
Reservoir Dogs: Just a small change from "while in the water with teammate" to "while in the water with a teammate"
Who's laughing now?: A small change from "the only one who is not been knocked out" to "the only one who has not been knocked out"
Run Forest Run: A small addition from "touchdown within 15 second" to "score a touchdown within 15 second_s_"
Roy Makaay: Similar to Run Forest Run, from "goal within 10 seconds" to "score a goal within 10 seconds"
Bowling Alley Cat: Similar to the last two, from "hit the hockey and" to "hit the hockey puck and"
Surfer Dogs: Similar to Reservoir Dogs, from "win one round with teammate" to "win one round with a teammate"
Wreck-it Ralph: I think it would read better if it was changed from "after all levers were broken" to "after all levers are broken"
Airline VIP: It's sort of fine as is but might read better if you change it from "ride in a launched trebuchet" to "get launched from a trebuchet" or if you prefer: "be launched from a trebuchet"
Fireworks: Just a minor change from "grab missile for one second for 3 times" to "grab a missile for one second for 3 different times" so it reads "grab a missile for one second 3 different times"
Ice Block: This one would read better if you changed it from "freeze yourself from being eliminated by the mist" to "freeze yourself from to avoid being eliminated by the mist" so it reads "freeze yourself to avoid being eliminated by the mist"