I've now 100% Guacamelee. One thing I really enjoyed about the game is that the really difficult stuff (which in my opinion also tended to be the most interesting stuff) is all largely optional. There are stages which riff on Mega Man, others which push the wall running and wall jumping mechanics to levels which are simply crazy, and there are even stages which require such a deft use of the combat mechanics that it raises the game to a level of complexity that might never be appreciated otherwise.
In the pantheon of Super Metroid-inspired adventure games, Guacamelee is definitely one of the better ones.
I also just started playing Papo & Yo, a game I always found intriguing. So far the puzzles have been pretty easy but also quite interesting. The way in which Papo interacts with the environment and the way that scale has been utilised by the game are really neat, and there are mechanics in there that I'm very much interested to see develop further.
Definitely a game I want to put more time into.