Originally a collection of mods, Rain World: Downpour usually feels tonally closer to base game Hunter as you control superpowered slugcats in areas brimming with apex predators; the oppressive, gameplay-informed tone and intriguing, generally believable ecosystem are diminished here in favor of combat mechanics and big story beats, but in that regard, I think it largely succeeds. The new slugcats are fun to play and the new regions are frequently beautiful and awe-inspiring, rivaling and arguably surpassing the best set-pieces of the base game. There is an impressive amount of effort put into not only spriting the new regions but also remixing the old ones to portray different points in the timeline, creating a contrast between a lively past and a miserable future. The original Rain World was humbling in its implication of decay but in Downpour we get to see it happen ourselves, and it delivers a surprising amount of emotional heft.

You can tell that it used to be a mod sometimes, though. As interesting and fun as the new slugcats are, they are powerful and silly in a way that the original game would not have entertained, and this serves to mostly divorce the player from the base game’s feeling of being like a weak, unremarkable animal. The worst example of this mod-feeling and, in my opinion, the weakest aspect of the expansion is the new creatures: sparing a handful of exceptions, they are either syntheses of existing ones - generally executed in ways that feel cheesy(?) and jarring - or variations on existing ones - which are interesting, but not particularly innovative. Between this and the unrelenting spam of predators you have to deal with, it can be pretty hard to take the new content seriously as a supposed actual ecosystem (as opposed to just a deluge of video game enemies placed there for you to deal with) which is disappointing.

Downpour doesn’t quite feel like playing Rain World again, but that’s fine - I don’t think anything ever will. The original game is an utterly singular experience; its magical claustrophobia - the terror and beauty of fighting against all odds for dear life, crawling through the reclaimed pipes of ancient machines, their purposes and forms shimmering like mirages just beyond your capacity for understanding - would’ve never come to be if any of its constituent parts were changed at all. Every single bold gameplay decision, minimalist UI element, and example of art direction informs its ludo-narratively perfect, spiritual profoundness. But outside of the holistic, Rain World is also a game made out of incredibly good gamey parts: its combat is high stakes and fun - Downpour has more of that, better. Its lore is creative and fascinating, and its characters are lovable - Downpour has more of that, too. If you enjoy any of these aspects of the base game, Downpour will be worth your time and money. Despite being somewhat flawed in a few ways, Downpour is a commendable, impressive, and love-filled community-driven expansion that reveres the base game, and it deserves the positive attention the devs gave it. And even if you don’t like what it does, it's implemented in a way that leaves the original experience intact and default.