This is an attempt at what I hope will be a complete list, eventually, of all the instances in Guacamelee where Drinkbox Studios (the developer) included a direct reference to another video game. Yes, the whole experience is modeled after the Metroidvania rubric. Within that confine, there are countless allusions at play. Let's assume those, and move on to the good stuff.
All screenshots were taken from the PS Vita version of Guacamelee, in no particular order. (As these screenshots are from all over the game, light spoilers may apply)