January 14, 2015
The formation of collectable items in Score Attack, Stage 6, is shaped like Kirby.
January 6, 2016
One of the comic strips in the game, entitled "Kirby's Closet", has Qbby dressing up with the sword and hat from Kirby's Ultra Sword form. The comic ends with Qbby turning around to discover that Kirby is watching him.
Kirby: Planet Robobot
April 28, 2016
One of the rare stickers in the game, found in Stage 7 of Rhythm Route, is a Qbby artwork.
February 2, 2017
Some of the comic strips have the same gag as the previous game, with Qbby dressing up as Kirby only to find out that Kirby is watching him. These include Qbby dressing up as Hammer Kirby, and him dressing up in an armor imitating Kirby's Robobot Armor, only to have Kirby show up in the original armor.
The game also features compatibility with the four Kirby amiibo, that unlock Qbby skins based on the respective character, as well as changing Qbby's blocks into Sar Blocks from the Kirby series.
Scanning a Kirby, King Dedede or Meta King amiibo from the Super Smash Bros. series has the same effect, but that's considered incidental, since the developers likely had the Kirby line of amiibo in mind when including the feature, as promotional images also imply.
Team Kirby Crash Deluxe
April 12, 2017
This game features compatibility with the Qbby amiibo, which awards 20 Fragments when scanned. This is the same effect as scanning amiibo from the Kirby series.
Kirby Battle Royale
November 3, 2017
Scanning the Qbby amiibo will unlock the Qbby hat, a cosmetic headgear for Bomb Kirby.
Kirby: Star Allies
March 16, 2018
One of the Stone Kirby transformations is Mount Fuji with a small Qbby sitting on a building.
The game also features compatibility with the Qbby amiibo, which awards two Picture Pieces, a Maxim Tomato, and two Point Stars when scanned. This is the same effect as scanning amiibo from the Kirby series.
Copyrights for both series are held by HAL Laboratory.