I've been hearing the term Metroidvania thrown around in recent years to describe games such as Cave Story and Megaman ZX, but have never quite understood what it actually means.
What does Metroidvania mean? What sort of game mechanics do these games share?
"Metroidvania" is a term used to describe a sort of exploratory 2D platforming game. It comes from the original games of the Metroid series and some of the middle-era of Castlevania games (most notably "Symphony of the Night", which is what primarily gave birth to the term).
The most defining feature is usually the world. Rather than have set stages or a world map, the entire game takes place inside one giant map, which you must traverse about. Not just any map, but typically a very complex map filled with all kinds of secrets. The map is typically divided into sectors, more in an aesthetic fashion to denote that the denizens and dangers will be different. Sometimes you have teleports to assist you in travel, but other times you just have to remember where to go in the map.
There's various elements at play in the exploration. There's typically tidbits hidden in spots, or puzzles that have to be returned to when you find appropriate equipment. The exploration is also non-linear - your limits of progression through the map are by various tools or powerups that you need to acquire, but the order in which you must acquire some of these tools is not set. And in many choices, there are many paths to get those tools, or even get past obstacles without those tools.
A very popular element of these games, especially in the Metroid franchise, is the concept of "sequence breaking". Using special tricks or otherwise mastering the utility of your basic abilities, you can sometimes access items and areas far earlier than the game expects you to.
As far as I know, Metroidvania games have always been 2D platforming games. Aside from the elements of exploration, the actual gameplay of Metroidvania games vary widely.
The term "Metroidvania" comes from combining the titles from the game series Metroid and Castlevania, and is used to describe other games that use a similar style of progression as these games.
The defining feature is usually that the game world is made up of inter-connected tunnels, passageways, rooms, etc., with some sections initially inaccessible due to a barrier of some sort. As you progress through the game, you will acquire new capabilities that will allow you to pass those barriers, opening up access to new areas. For example, it's common in the Castlevania games to acquire an item that grants the ability to double-jump, which will allow you to reach platforms that were previously too high to jump to. Games of this style typically involve quite a bit of backtracking whenever a new capability is acquired, as you go back and find all the locations where this new ability allows you to progress further than you were previously able to.
People apply varying levels of strictness to the "Metroidvania" term. Some will only consider it valid if the game is also 2D, excluding games such as the Metroid Prime series, even though the gameplay style is basically the same.
Metroidvania is a term describing a game that combines elements commonly found in Metroid and Castlevania games. While what exactly constitutes the Metroidvania category varies from person to person, I consider these to be the defining characteristics
Others can feel free to edit this if anything I listed isn't true to every Metroidvania game, or if I missed something that is really obvious.
