"Metroidvania<a]<="" a=""> is a genre of action-adventure video games focused on guided non-linearity and utility-gated exploration and progression. The term is a portmanteau of the names of the video game series Metroid and Castlevania, with games in the genre borrowing from both series. Typically based on two-dimensional, sidescrolling platform gameplay, Metroidvania games feature a large interconnected world map the player can explore, though access to parts of the world is often limited by doors or other obstacles that can only be passed once the player has acquired special items, tools, weapons, abilities, or knowledge within the game. Acquiring such improvements can also aid the player in defeating more difficult enemies and locating shortcuts and secret areas, and often includes retracing one's steps across the map."</a]<="">

Past the first sentence it's all explained. It's not limited to action, and even is mostly exploration and non-linearity.