Guacamelee has a TON of references to games, internet memes, etc. The following are most of them and how they appear in the game:
A Christmas Story
At the highest point inside the church is a secret message written in the language from Fez. Translated it reads: "Be sure to drink your Ovaltine, a reference to a code cracked in the film A Chistmas Story broadcast by the radio program Little Orphan Annie.
A Winner Is You
The funny quote from the NES classic "Pro Wrestling" is referenced when you complete the game.
There's a poster just outside the Desert entrance showing the Dark Knight and Bane facing each other.
Business Cat and Bachelor Frog internet memes
A poster in Pueblucho can be found advertising a fight between Gato Negocio vs Rana Soltero
A poster saying "Casa Crashers" can be found with the four characters.
An outline of Simon Belmont fighting an undead foe with his whip can be seen...
a Statue of Donkey Kong holding up a barrel can be found.
There is a cactus in the desert with the same shape as the Cactuar characters from the Final Fantasy series.
a poster referencing this famous internet can can be seen with the words Gato Grunos Cat Food
Insanity Wolf meme
a poster in Santa Luchita shows a similar wolf with the words Loco Lobo Tequila.
The title character from Journey can be seen laying in Sierra Morena.
Legend of Zelda
The center stained-glass window in the church displays a luchador in familiar green clothing with the Triforce behind him. There is also a poster saying "El Linko with a Link-look-alike on it as well.
Majora's Mask and Megaman
A poster in Pueblucho can be found advertising a fight between La Mascara vs Mega Hombre. A sihoulette of Mega Man can also be seein in the game.
An outline of the Flower power-up and 8-bit can be seen in the game as well as a poster with saying "Los Super Hermanos" and two wrestlers resembling Mario and Luigi.
There are statues that bear a striking resemblance to metroids throughout the game. You also obtian power ups from statues called Choozos that also have the same shape and pose as the Chozo statues from the Metroid series.
There is a building with a sign saying "Mine Forever". If you visit the same building in "The Dead World", the sign changes to "The Nether Portal".
There are bricks in an area of the game that show the pixelated aliens from the classic game.
Super Meat Boy and N+
A poster advertising "Nino de Carne v.s. el Ninja" is a reference to Super Meat Boy and N+.
Tales From Space: Mutant Blobs Attack
A poster with the phrase "Los Limones Mutantes Atacan" is a reference to the 2012 PS Vita game.
Team Fortress 2
A poster saying Caballeros Churros is a reference to The Gentleman meme stemming from Team Fortress 2.
There is a building with the a sign above that reads Viva Pinatas.
a framed picture of what is either Wario or Booster from Super Mario RPG can be seen inside a house.
Wreck It Ralph
There is a poster with a guy resembling Ralph and the phrase Build It Bill.
Note: View the following video to see some of the easter eggs in the game.