Uugghhhhh it’s so good. Really masterfully designed in how it gets you exploring both the environments and game mechanics, though it can be cryptic to its own detriment. The non-player-creatures stand out as highly believable, unsettlingly real animals that act in unpredictable but natural ways. it’s also hard to fathom how such a small team could achieve such heights in visual (gorgeous, semi-procedural environment art) and audio (truly creepy and strange creature noises and tasteful, huge ambient soundscapes that are admittedly a little hampered by the sort of forgettable soundtrack—i think a stronger choice would have been no music at all with a different method of conveying that you are e.g. about to be eaten by some kind of juiced up crocodile) design. I really was not prepared for the atmosphere of this game. it’s really a treat.
Rain World knows that it is a simple game. you are not rewarded for exploration with a double jump or bigger muscles to throw rocks harder but with cool new places encrusted with cool new layers of cool new types of crust, and with cool weird new organisms that make you squirm with disgust(ed delight). Getting eaten by something new in a new, exotic, concrete bolgia is its own reward. Rain World is not a horror game but it is scary in the way that real life is scary. anything can happen and you don’t know what will until it does. even then, you can only prepare for what you know has happened before. Rain World is not above surprising you with a new type of dying. it’s bold but it works because it knows what it wants to be and how all its constituent parts should be in order to meet that goal.
the major problem with Rain World is just that it can be very hard to tell what you are really supposed to do or where to go, and the game doesn’t really account for this much. the slow pace of the platforming and level layouts can make experimentation annoying, especially while trying to avoid death by random predator or just flopping off a cliff. it’s difficult to remember how to get around, even with the map, which has been purposefully restricted in utility. maybe I am a new school gamer, but any time i need to whip out the pencil and paper to remember which areas link where (which I have got very close to doing, I still don’t fucken remember how to get to half the map) I think as a designer you have failed unless the integrity of the game is built around that, and I still probably wouldn’t play even Wizardry without an automap. I understand the intention of mystery and letting the player discover things, but I think some of the discoveries in Rain World are more frustrating than satisfying (I could have done X the whole time?).
I happily recommend Rain World but please know that you are looking at a very specific type of game that can be frustrating to some people. It feels in some sense like a game for game developers. I just wanna take it apart and look at its insides, and those of the people who made it.