Just Dance 2020

This requires you to score 3 stars or better on every base song in the game. It's worth noting (as hinted in the description though this wasn't clear to me) that alternate or extreme versions of songs do not count.

I also believe playing in World Dance Floor doesn't count, or at least I had mixed results there.

There's 41 songs (listed below sorted by length):

1:28 Baby Shark – Pinkfong - (Duet)
2:23 Infernal Gallop (Can-Can) – The Just Dance Orchestra - (Duet)
2:43 Con Altura – ROSALÍA & J Balvin Ft. El Guincho - (Solo)
2:43 Old Town Road (Remix) – Lil Nas X Ft. Billy Ray Cyrus - (Solo)
2:44 Skibidi – Little Big - (Duet)
2:45 Soy Yo – Bomba Estéreo - (Solo)
2:47 Everybody (Backstreet’s Back) – Millennium Alert - (Quartet)
2:47 Só Depois Do Carnaval – Lexa - (Solo)
2:50 Sushi – Merk & Kremont - (Solo)
2:55 Bassa Sababa – Netta - (Solo)
2:58 7 rings – Ariana Grande - (Trio)
2:59 Stop Movin’ – Royal Republic - (Trio)
3:04 365 – Zedd & Katy Perry - (Solo)
3:04 MA ITŪ – Stella Mwangi - (Solo)
3:04 Ugly Beauty (怪美的) – Jolin Tsai (蔡依林) - (Trio)
3:04 Vodovorot – XS Project - (Solo)
3:07 Bad Boy – Riton & Kah-Lo - (Duet)
3:08 Fit But You Know It – The Streets - (Solo)
3:12 High Hopes – Panic! At The Disco - (Quartet)
3:14 Kill This Love – BLACKPINK - (Quartet)
3:15 Con Calma – Daddy Yankee Ft. Snow - (Duet)
3:15 Keep In Touch – JD McCrary - (Solo)
3:16 bad guy – Billie Eilish - (Solo)
3:16 Rain Over Me – Pitbull Ft. Marc Anthony - (Solo)
3:16 Talk – Khalid - (Solo)
3:16 Into the Unknown – Disney’s Frozen 2 - (Solo)
3:19 Always Look on The Bright Side of Life – The Frankie Bostello Orchestra - (Quartet)
3:19 Policeman – Eva Simons Ft. Konshens - (Trio)
3:22 God Is A Woman – Ariana Grande - (Solo)
3:27 Fancy Footwork – Chromeo - (Solo)
3:32 Le Bal Masqué – Dr. Creole - (Quartet)
3:33 Just An Illusion – Equinox Stars - (Duet)
3:34 I Am the Best (내가 제일 잘 나) – 2NE1 - (Trio)
3:35 My New Swag (我的新衣) – VAVA Ft. Ty. & Nina Wang - (Solo)
3:37 Bangarang – Skrillex Ft. Sirah - (Solo)
3:37 FANCY – TWICE (트와이스) - (Trio)
3:37 Taki Taki – DJ Snake Ft. Selena Gomez, Ozuna, Cardi B - (Solo)
3:38 Tel Aviv – Omer Adam Ft. Arisa - (Trio)
3:46 I Don’t Care – Ed Sheeran & Justin Bieber - (Solo)
4:08 The Time (Dirty Bit) – Black Eyed Peas - (Quartet)
4:11 I Like It – Cardi B, Bad Bunny & J Balvin - (Trio)

Score 3-stars or better on each of these and the achievement is yours.

I don't recall what the score cutoff for 3 stars is (11,000 is superstar, so I'm guessing it's 10,000 for 5 star, 9,000 for 4 star, and 8,000 for 3 star, but not positive on that).

You can also look at the achievement tracker to see how close you are (each song you do increments that tracker by ~2-3%)

If you find the tracker stalls, see the comments below for some tips from CandidFever3.