Welcome back! This is a neat level, I dig the aesthetic... but I feel it's a bit rough around the edges. A bunch of setups involving piranha plants or snowball throwing enemies feel like they are supposed to inflict a sense of challenge, instead of actually being a challenge. Take the first platform ride upwards for example, it can be passed while barely moving at all the whole time. Also a number of piranha plants while riding the platforms simply won't harm you unless you intentionally jump, which kind of makes these feel like a waiting game. And man, I was sad to see the spinning platforms confined to that one section, and the fact that the flurries didn't receive that much love throughout the level! I feel those elements could spice up the gameplay nicely, perhaps some nice setups where they interact with other elements like the snowballs and platforms. But I still enjoyed your level, and some setups like the final platform ride was pretty clever. I'd like to see what you come up with in the future!
Also this is more of a general complaint about SMBX, but god...I absolutely despise slippery blocks in SMBX. The physics of SMBX are weird enough as is, and slippery blocks just make it even worse.