Warning : I'm a rabid, unreasonable metroidvania hater. If you're a fan of the genre prepare for venom.
I used to think I was into metroidvania games, but the more I played them, the more bitter I got & the more convinced I became that metroidvania is perhaps the worst genre in gaming. It's a genre that consistently fails to take advantage of its interesting design elements, and constantly devalues and butchers itself.
These games turn exploration into staring at a map screen without engaging with the environment. These games turn discovery into a shopping checklist. They reduce level design into repetitive hallways. If you want someone to despise exploration and beg for 2D beat 'em up level design, just get them to play nothing but metroidvania games for a couple of years.
But among that sea of trash, there's absolute gems like Rain World. Games that deliver on every promise of the metroidvania genre so well that to include them in that pile would be an insult to Rain World itself. So instead think of it like this - there's the stinky diseased dumping ground that leaks into other genres called "metroidvania", and then there's the shining pristine beacon of hope called [ World Mastery Games™ ], my platonic ideal of a metroidvania. And Rain World sits at the top of that golden tower.
The idea of world mastery isn't really new and Rain World certainly isn't the only game to capture it decently well, even if nothing quite matches it. These sorts of games have existed for quite a while in different forms - STALKER being a really good example, especially with some mods like Call of Chernobyl, some mods that add more enemies/stalkers and Misery. Resident Evil 1/RE1make have aspects of this too thanks to their severely limited inventory, limited resources & the open ended mansion with a lot of different routes (& Crimsonheads soft-blocking routes in RE1make). Fan made randomizers in games like Zelda 1 and LTTP shift the games towards world mastery.
Metroidvania games themselves actually gain these elements during some self imposed challenge runs such as speedruns, but the potential is mostly wasted because developers treat the genre as disposable trash.
Metroidvanias are pain
World mastery games and metroidvania games share many of the same elements. They have big interconnected environments with interesting gating that makes the routes you take more involved than simply picking a direction and holding forward. They have a mix of gameplay styles - exploration, platforming, combat, perhaps stealth, perhaps RPG elements. They have sequence breaking, they have backtracking, they have ability-based gating of both the soft and sometimes hard varieties.
Metroidvania games use their worlds as content delivery mechanisms - their job is to connect one piece of prebaked content with another piece of prebaked content, and perhaps add a few more access points than you'd have in a linear game for sequence breaking. Different elements exist almost counter to each other - the games have backtracking as a defining feature, but never do anything with it and as a result have to constantly undermine it with shortcuts. They don't actually want you to go through the same area more than a time or two. "Exploration" itself is constantly undermined with a really detailed map and obvious ability gates, which are often color-coded. The genre is afraid of its own conventions.
PURITY
World mastery games aren't ashamed of the elements that make them up and embrace them, trying to flesh them out. They aren't trying to hide their backtracking, they tend to give meaning to it, either within the same run or across several runs. They will have life simulation systems, indepth movement mechanics & layered levels that let you take advantage of them, challenges that remain tricky even if you've seen them a bunch of times, interesting resource economies, randomized elements that force you to rethink your approach, constantly shifting goals, survival-esque time pressures that force you to branch out carefully or make reckless mistakes, and other such stuff. They will embrace exploration - they might abandon map screens entirely, or reduce the information said maps give you.
The games are built to reward knowledge of the world itself rather than any specific level, or even mechanics. The better you know the layout of the levels, the more efficiently you can do what you need to do like gather resources, avoid enemies, come up with plans on the spot, etc. The world design itself tends to be deeply integrated into combat. In STALKER this is mostly manifested as the amount of cover you get, some anomalies you can use to your advantage, terrain/buildings you can use to abuse the game's stealth system and ambush enemies. In Rain World, the stealth depends on terrain, and the viability/effectiveness of combat is directly dependent on which weapons/objects you're carrying or have next to you and what sorta terrain you're dealing with. In both games you will play better if you have a robust, highly detailed mental map of the world itself.
Needless to say, roguelike-inspired survival games don't quite fit the bill either - they have a certain degree of world mastery as well, but you absolutely need a stable world underneath all the randomized elements. Otherwise you're mastering systems & mechanics, not the particular, hand crafted layout of a world. Zelda 1/LTTP randomizers are a better representation of the style than RL survival games. The games need enough randomized elements to constantly force players to engage with different routes through the game & as much of the world as possible, but not enough to undermine the planning aspect.
Just wanted to do a messy rant. Will probably expand on this in a dedicated Rain World review, after I play that game enough. So far game's shaping up to be one of my fav ever, giving me exactly what I loved about STALKER in a more refined, interesting & condensed form. Go play it.
