More and new clues:

#21

• Getting to use the sword is a novelty, and often tricky.
• Shooting laser beams at your opponent is also fun.
• It's the second entry in a series that's still going strong to this day.
• One thing I loved about the game was the little cut scene vignettes you unlock when you complete the single player part of the game with each different character.
• You also unlock extra playable characters by completing the game with a character that each one is connected to in some way.
• As already guessed, it's a fighting game. The second entry in the series.
• It's a PS1 game.

#19

• Back on the PS3 when PSN was just for smaller games, not full downloads of major releases, this was one of the biggest games on the service and also the best.
• It's a racing game.
• Most of the tracks come from previous entries in the series.
• It received an expansion pack roughly a year after its initial release.

#14

• Anyone who managed to complete this PS1 game without a guide book (which I used but still found the game to be difficult) or cheats certainly has my respect. Difficulty is mostly derived from the fact that levels are full of deadly traps, as well as lots of timed puzzles that kill you if not completed in time, and it not always being obvious where to go or what to do next, despite levels being very linear.

#13

• I'm not a fan of JRPGs, but this classic game and the series it started is a major exception.

#12

• The transition from 2D to 3D was huge for this open world franchise, and somehow not only was nothing lost gameplay-wise in the transition, but it was actually added to in significant ways. 

Hoping to clear up my current hints a bit before I start adding more games.

21) On my "CD shelve" this game takes up nearly an entire row.

Hint 2: Not because the box is quite that large, but because there are several of them.

Hint 3: Most of the boxes are expansions.

Hint 4: It's not Sims game.

20) If the protagonist of this game had been playable in Smash Bros. they could have up to 4 different move sets.

Hint 2: 1 "base" and 3 transformations.

Hint 3: There are already character(s) in Smash Bros. that share a name with the particular protag.

Hint 4: This has been equivalent of a trick question, since this character technically is in Smash, only it's him from the previous entry, and thus he doesn't really have moves relating to this game.

19) While this game is in some ways a return to the basics for this series, the additions it makes to your arsenal are some of the more original.

Hint 2: Includes a new mad villain as well as the classic one.

18) Brings a new meaning to twin-stick controls.

Hint 2: It's not Brothers: A Tale of Two Sons, but control-wise there is a similarity.

Hint 3: You essentially control two characters who are bound by...

17) 2019 2020 2021 2022

Hint 2: Obviously the game has been previously released or it wouldn't be on my list, but these dates can be found on the game's website currently.

Hint 3: The dates are for the expanded version of this game which is coming in early 2022, promise.

Apparently I made this set of hints quite tricky, as both #19 and #18 went unguessed. Let's see if it can get a little easier with the next hints.

#17: The Mac OS version of this game (at least) featured an interesting anti-piracy measure where you had to look up letters in the manual.

Hint 2: Once you find the correct letter, you can drink the correct bottle and the door to the next level opens. Drink the wrong one, and die.

Hint 3: This actually mirrors the rest of the game, most bottles are for health, while some take health. You see this by the color of its plume. Obviously though there is no plume in the lettered bottles because that would be too easy to guess.

Hint 4: The levels start down in a grey-coloured dungeon, presumably the place where you were imprisoned, until the switch to the more elaborately decorated red and golden floors of the palace.

#16: Breaking a mirror brings bad luck. Maybe the bad guy in this game shouldn't have broken the mirror.

Hint 2: The bad guy also should've known that the mirror would break in only four pieces, and that they would conveniently end up at the end of as many sinister places.

Hint 3: The first is in a desert, the second on a snowy peak, the third in a lost woods and the fourth in the sky. Guessed by Link_Nines.XBC - The Legend of Zelda: Twilight Princess

#15: This game was named something else where I live due to trademark issues.

Hint 2: Just like this game's predecessor. However that one was called differently. After this game, new games took the real name of the franchise. Guessed by TruckOSaurus - Lylat Wars/Star Fox 64

#14: Beach balls can roll on all sides.

More games to guess:

#17: Elirium 115 (first game).

#16: Time travel in the john.

#15: A shrine can revive your horse, if you managed to kill it. Guessed by drbunnig.

#14: Sorry to keep you waiting.

#13: On the first day man was granted a soul and with it clarity.

16.  Day of the Tentacle

14.  Grim Fandango

#16: Hint: Huge creatures fought each other to the death.
#15: Hint: A white glowing creature is the forests last hope.
#14: Hint: A still devisive entry in it's franchise that is mostly praised highly.

16.  Xenoblade Chronicles

15.  Ori and the Blind Forest

14.  Wind Waker

16 yes

15 yes

14 No, pretty sure WW was only devisive early on because of the art style. And the prople who disliked it hadn't even played it.

I've played Wind Waker and it is one of my least favorite games ever.

#16: Yes, obviously. I thought I get away with a bit more obvious hint, because the game is more obscure.

#14: Nope. I clearly should play Grim Fandango one of these days though, I like most LucasArts adventure, I have a strong feeling this holds true for Grim Fandango as well.