I didn't get very far into this, so take what I say here with a grain of salt, but I got disinterested very quickly. A lot of aspects of Rain World are good, and I do think the platforming itself is fun, but dealing with enemies is too annoying for me to deal with.

The bulk of what I played is that element that horror games and stealth games share: sitting and waiting for the monster/enemy to walk away. Once they finally do so, you enter the next screen and get immediately one-shotted by the enemy waiting at the entrance. Then, after you repeat that 5+ minute section of waiting and light platforming, the enemy just... isn't there this time, and you can go a bit further, only to get one-shotted by a new enemy, etc. I didn't feel like I was overcoming anything or making progress, since the solution to the encounter was always to cower or run back and forth until the enemies got as bored as I was.