These achievements are significantly easier if you do them by yourself, or in conjunction with others who are working towards earning them. For the sake of this guide, I'll assume that is what you're doing.

If an achievement does NOT mention the number of players needed, it can be done with the minimum players for that game.

You can use an extension such as SessionBox[sessionbox.io] for Chrome to allow you to easily have multiple sessions at once.

Thank you for checking out this guide. If you found it helpful, please give it a Thumbs Up and consider giving me an Award. If you need help, please ask in the comments.

Fool Me Three Times: Fool the same player 3 times in a game
Requires 4+ players, otherwise you won't have enough guesses with each person.

Palette Cleanser: Use all 3 colors in an animation
This is very easy. It can even be done when creating your avatar before a game starts.

Proof of Friends: Finish a game in the Friend Mode
Just load up the 2nd game mode, Friend Mode, and finish the game.

Accomplishment:
For your answer to any drawing, include the word "Accomplishment". Another player may have to select it as well, but I'm not sure if that is required or not. Will award as soon as that image is completed.

It's Anyone's Game: Spin the wheel after all players have enough points to win the game
If you give identical answers for both players, they'll get the same amount of points and you should be able to get them both over 20,000 fairly evenly. I'd avoid placing slices down to help keep it even as well. For ones with a speed timer, pause the game and input the correct answer + click submit for both players, then unpause.

Power Slice Hero: Earn the power slice in every round in 1 game
Have the same player get the most points on the 3rd question in each round of the game (likely 2 rounds, if it's a 2 player game).

The Big Score: Earn more than 10,000 points from a single slice
I recommend having as many players as possible to try and make this easier. A full 8, if possibe. If you can finish the wheel on round 3 and get the 1.5x bonus, you'll be guaranteed to get it. Otherwise, try and get lucky with a x2 spin slice. Remember that you can place multiple of your slices on 1 slice, to increase the reward. On the trivia rounds, try and get as few points as possible, spread winnings out evenly between questions, and don't answer at all for any round that is a match-the-columns, which is greater, or what am i thinking of? Make sure to pause, so that you can properly answer for all your players + plan out your order of points for each question.

True Enlightenment: Get your question answered 2 games in a row
Win 2 games in a row with the same player.

Totally Synergized: Get 2 synergies in 1 round
Requires 5+ players, in order to count as a Synergy. A Synergy is when all players + audience votes for your answer. Do this twice in 1 round.

Over the Rainbow: Get a rainbow bonus in all 3 rounds
Requires 4+ players. A rainbow bonus is awarded when you use words from 3 different players AND your answer receives more votes. Get one of these in each of the 3 rounds.

Logo Poke-a: Poke the logo 40 times
This is the sad briefcase with "Job Job" written on it that appears during the tutorial or after you've submitted your answers.

Workin 9 to 5: Play Job Job 5 days in a row, Monday thru Friday, between 9am and 5pm
As it is in the description, play and finish a game of Job Job 5 days in a row, Monday to Friday, starting after 9am and finishing before 5pm in your local time zone.

In The Dark: In round 1, picked the 8th place door on 1st guess
In Round 1, Player 1 selects the 1st 4 options, Player 2 selects options 4-7. Then, on the first Door guess, pick option 8.

Perfect Round: Pick all correct doors for an entire round
In Round 1 or 2, both players select the same 4 answers in the same order. Then select the correct 3 answers that are asked for.

All Alone: Win a game by yourself vs 9 opponents
Requires 10 players. The hardest part of this is setting up a 10 player game solo. Once you've done that, assign 9 players to one team, then start the game. In rounds 1 and 2, have all 10 players select the same answers in the same order, then have the solo player answer correctly and the players on the team of 9 answer incorrectly. For round 3, have 9 of the players answer the same 5 answers in the same order and then have the 10th player answer the first three the same but have fourth and fifth answers be unique... this will insure that all 8 answers have different point values. Then, again, have the solo player answer correctly on the 8th and 7th answers to win (with team of 9 answering incorrectly).

Vs the World: In Streamer Mode, play against an audience of 1000+
Ok, buckle up, cause this is one challenging achievement to do solo, logistically.
Requires 1002 players. Load up The Poll. Go to settings and change it to 2 players max. Start a game in Streamer Mode and then add 2 players. Now the fun begins. How will you get to 1000 audience members? Make sure you have SessionBox. It will also benefit you to get a mouse recorder; I recommend TinyTask[tinytask.en.softonic.com]. You will also need Chrome, Firefox, Edge, and Opera... plus either a 5th browser or a second PC. All with SessionBox.

Start a new window of Chrome, go to jackbox.tv, and log into the game as an audience member. Then use TinyTask to make a macro of opening SessionBox, go to jackbox.tv, input the room and a name, and join audience. Now, run the macro 240ish more times. I found that it will stop connecting to jackbox on Chrome after 246 audience members. Switch to Firefox and repeat. I found that it will stop connecting to jackbox on Firefox after 199 audience members (445 total). Switch to Edge and repeat. I found that it will stop connecting to jackbox on Edge after 254 audience members (699 total). Switch to Opera and repeat. I found that it will stop connecting to jackbox on Opera after 255 audience members (954 total). Switch to second PC or 5th browser and repeat to 1000.

The achievement will trigger immediately upon having 1000 audience members. You do not need to start the game, let alone finish it. Some other notes: This took me a bit under 2 hours to complete. Be warned that a game of jackbox will time out after a certain period... it is somewhere north of 2 hours (but less than 7 hours). I found that opening 900+ jackbox tabs did not increase my CPU much at all (just the base value from opening additional browsers), but it did add about 10MB of RAM per tab opened, or about 10GB in total. Good luck and have fun with this one!

EDIT: I checked in on SessionBox 2 days after getting the achievement, and I'm locked out of the extension unless I pay for the Commercial tier. So, be warned!

Elementary: At least 1 person gets every case correct, including Cold Cases
Will award at the end of the game. Have all players get every case correct, just to be sure.

Belle of the Ball: Attempt to murder 1 person 10 times
Have 3 players all incorrectly guess the 4th player's accomplice 3 times and then one of them correctly guesses it. It will be the only option remaining, so 10 attempts is the most you can have.

Dead of Night: Play the game at Midnight
Start a game before Midnight in your time zone. I'd recommend around 11:50 to be safe. The achievement will award when you FINISH the game, after the winner is announced.

Lashed Out: Murder an accomplice named "Schmitty"
Name one of the accomplices "Schmitty" and then murder that accomplice.

Again, thank you for reading! If this guide helped you, please give it a thumbs up or an award. Cheers, -Tass