TBoI: Rebirth                        | 637 Achievements
Stardew Valley                     | 49 Achievements
Hades                                   | 49 Achievements
Spelunky 2                           | 32 Achievements
IdleOn                                  | 61 Achievements  
Animal Well                         | 20 Achievements  
Golf With Your Friends        | 39 Achievements
Port of Call                          | 7 Achievements
Refunct                                | 10 Achievements
Mandagon                           | 5 Achievements
Zup!                                     | 118 Achievements
Forager                                | 103 Achievements
SEUM: SfH                           | 30 Achievements
Brawlhalla                            | 39 Achievements
Spongebob BfBB: Re           | 32 Achievements
Runescape                           | 20 Achievements
Ori atbf: definitive               | 57 Achievements
Celeste                                | 32 Achievements
Plantera 2: Golden Acorn    | 40 Achievements
Nova Lands                         | 24 Achievements
Slay the Spire                      | 46 Achievements
Vampire Survivors               | 196 Achievements
Children of Morta                | 45 Achievements
Nodebuster                         | 13 Achievements
Castlevania: Dominus         | 52 Achievements

Games may differ because of newly added achievements, that's why there's the amount of achievements at the time of the 100% completion :)