Cameos and References
This is a list of games and other media that have referenced Cave Story in some way or form. This page is still a work in progress and is by no means exhaustive.
Chinfish (Egg Fish) appears as one of the fish that can be caught in this game.
Curly Brace can be unlocked as a playable character in the Switch and PS4 ports after completing quest 12 (Boss Battle: Giga Tadpole).
Quote and Curly Brace are both playable characters and the game's story is centered around the Red Crystal.
Quote and Curly Brace are both playable characters in Blade Strangers.
Curly can be unlocked as a playable character in 1001 Spikes by obtaining 30 golden skulls. She is equipped with a Booster 2.0 and her trademark machine gun.
A statue of Balrog can be found in a room behind that ledge to the right of the fire bomb enemy in the Clock Tower. You will need the Wing Boots to reach it.
Balrog can be found in Scenario 4 (Due Exaltation) within the Great Machine in a room accessible with the Lasso and the Jump Boots from Florius.
The Polaris, a reference to the Polar Star, can be unlocked by completing the Hollow 20 times.
The robot hat has a 0.4% chance to drop from Piranhas or Angler Fish in Terraria. It is a reference to the hat worn by Quote in Cave Story.
Paintings of Quote and Curly can be found on the second floor if you can be distracted long enough from trying to poke cats.
Quote is available as a playable character in the Good Friends Character Pack for BIT.TRIP Runner 2.
"Remember, Pit, you won't be fighting alone out there."
"You're going to send me a machine-gun-robot girlfriend?"
From the opening lines of the Powers
If you click on the SNES controller in the main menu of the Steam release of "Indie Game: The Movie" then you get an indie game character mix and match game.
Curly appears as an NPC in this game and makes a passing reference to the opening hell narration from Cave Story.
on the character select screen to select either Quote or Curly as your character.
In a segment of the game where you must cross a long disintegrating block bridge across spikes you will find a gap in the spikes leading to a hidden room, in that room you will find the "Squid Hat (ika)", which is described as "an absolutely cute white hat from the depths of a pixelated ocean".
I Wanna Kill the Guy
Curly is used as an optional dance off boss in chapter 3 of IWKTG v.052.
The Suite Life on Deck
The start point from Cave Story is shown in an arcade machine in season 2 episode "Goin' Bananas".