Good game, entertained me for 1 hour.
The rain gliding mechanic is a nice twist to the jump king movement, although I dislike that some jumps forced you to have to time your jump-charging immediately as you landed on a moving/slippery surface. This technique felt really finicky especially considering that you couldn't buffer a jump mid-air so that, as soon as you land whilst you are holding spacebar, you would charge a jump.
Occasionally, after being sped up with conveyor belts, I would glide off ledges that weren't rainsoaked (and with the balls almost acting as bumpers). Sometimes walls don't stop momentum, making for some jank falls.
Overall however, I liked most of the jumps and could find reliable setups for most of them, so I think the difficulty is fair.
The aesthetics are simply and pleasing, although I personally would have preferred more details on some walls. The lighting from the torches enhanced the gloomy mood for the inside rooms. The audio was basic but perfectly fine.
I think the shrine theme could be developed more as a story element, right now it feels shoe-horned in.