There's definitely an interesting base for a gameplay loop here, though in my personal opinion it overall felt quite slow because the clouds took forever to spawn. So I was never really overwhelmed or in much danger of letting them past unless I purposefully decided to.
Add onto that the fact that the "level goals" were very inflated compared to the actual speed I feel like. Which led to a lot of me just waiting to be able to use different mechanics, which did seem interesting by themselves, they just took awhile to actually be integrated into the game.
Overall though there's definitely an interesting concept here, that could lead to some more variety, I mainly just feel like the speed should be increased quite a bit to speed up the overall gameplay loop and make it a more challenging. Though also mixing up the spawns a bit more with more of them at once would definitely help.