I always expect these things to look pretty disturbing, but these are actually pretty cute.
I've only tried the unicorn one so far, but I really liked it. The mask itself is thicker and cushier than the plain ones I typically buy. They feel really high quality, and my skin responded very well to the serum. On the whole, my skin issues are fairly minimal: I have a bit of acne when my hormones are acting up, and my face tends toward oily otherwise (tho I find that heavy anti-acne products or products for oily skin tend to exacerbate the issue). I also don't have particularly sensitive skin, so I can only speak to my own experience here.
I'm planning to try the mermaid one today after I shower, and I've already ordered a second pack of these. They're more expensive than the 12 pack I usually buy from a different brand, but I like to splurge a little every once in a while and get something fun like these. Would definitely recommend.