#35: One of the best crossovers I've seen; conquer other domains with your monster partners.
#34: A massive change for a beloved RPG series; a great game but completely different from the sequel many wanted.
#33: The beginning of one of the Big N's current biggest hitters. A peaceful game with catchy music and infinite playability
#32: Journey with a team of monsters through two regions; with extra content and the first playable female character in the series.
#31: In a first for the series, a new generation launching on the same console as its predecessors.
#30: One of the grandest platformers of all time; a beloved icon goes on an epic journey.

#38 is Tetris (From Russia With Fun)
#37 is close! Tomb Raider II

#33: Animal Crossing?

#32: Pokemon Crystal?

#35 Pokémon Conquest?

#33 Animal Crossing

#32 Pokémon Gold & Silver?

#31 Pokémon Black & White

All correct!

I'll drop a couple more hints too:

#34: Previously allowed you to explore a 3D world; now you swap between the dimensions, with a limit on your time in 3D.
#30: For a character who never changed clothes when not using their powerups before; the costume options in this game are huge.

#34 Paper Mario

Hints for the next five games on my list:

#34: Sun Goddess.

#33: Fight, but this time without tripping.

#32: Featuring four generations of one of the most dysfunctional families in fighting game history.

#31: The leader of one of the factions in this RTS game is possibly an actual biblical character.

#30: Monkey and Trip.

#35
Chrono Trigger
(Change YoY: -3)

I really should get around to replaying Chrono Trigger one of these days. It's been years since the last time I did, and considering how great the game is it really is due another playthrough. I know many people consider it the greatest JRPG of all time, and while I wouldn't go quite that far, it certainly is one of the best ever. Time travel stories are always difficult to make work, and yet Square managed just that back in 1995 on the SNES. It really shows just have good they already were at telling stories in video games back then.

If there's one issue I have with the game, it's that I've never really liked the silent protagonist trope in RPGs. It's a very minor gripe, but it just leaves the main character a bit distant in the end. Regardless, if you haven't played the game yet you definitely should, especially as its now more easily available than ever before.

#34: Clearly Okami.

#35: Smash bros WiiU

Correct on both.

As #33 and #32 prove to be tricky, some more hints.

#34
a) As first rumours leaked about this mashup of two franchises, nobody thought that could work well together.
Guessed by Barkley: Mario+Rabbids: Kingdom Battle

#33
a) Fight the most enemies ever in this series, with this version also in HD.
b) After I defeat you, I make a hat out of you!
c) This is the HD-console port of a handheld game, which itself is an extended version.
d) The last game of the series before a new generational jump, which happened this year.
Guessed by Flilix: Monster Hunter Generations Ultimate

#32
a) A fairytale told in watercolors.
b) Will someone please explain how water falls with no rain?
c) He's a one-of-a-kind, mint-hunting, flying pig. An' I own him, he wears my mark.
d) We were afraid to never again see the soft, green hills of Lemuria.
Guessed by outlawauron: Child of Light

#31
a) Grow helpers.
Guessed by The_Liquid_Laser: Pikmin

#30
a) Return to this place with graphics this time.
Guessed by The_Liquid_Laser: Return to Zork